Answer:
Part 1)
![x=(g)/(c)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/pyl698rkfip33vos6gdgox9b38xymid3tb.png)
Part 2)
![a=(1)/(3b)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/mbr5pe4vrzotfhg0er4xbg49k1o4ner86w.png)
Part 3)
![a=(n+p)/(m)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/jxc12tbf7e7p1qwjrsveaio8uxjkgtq4gt.png)
Part 4)
![x=g-y+c](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gocwxek6ydy26xyc4hz9w67v48d6x9a641.png)
Part 5)
![x=(z)/(m-1)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/5knvjkms5sgjpxipdhuea7jvsswc3ef2uo.png)
Part 6)
![a=(g+b)/(c)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gph6mtetul72evcj4dltsxl7tqokvj1ukm.png)
Part 7)
![b=(A)/(h)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/hcnnecp13xm3jj6h00rmbw7lkq7bwe9397.png)
Part 8)
![W=(P)/(2)-L](https://img.qammunity.org/2020/formulas/mathematics/middle-school/923x4t41dafmmqwk7nrx2c81k5mly9tbx6.png)
Part 9)
![d=2Q-c](https://img.qammunity.org/2020/formulas/mathematics/middle-school/mdobzqai7mawngq62i7l2oknyhbxyw1khw.png)
Part 10)
![a=(Q)/(3+5c)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ryfldms93g94xoh017k25ijw3rtqpef2ce.png)
Part 11)
![N=(A))/(P-IR)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/782jz21isc8co6i5ahmcrk3y2676fmzj20.png)
Part 12)
![b=P-a-c](https://img.qammunity.org/2020/formulas/mathematics/middle-school/230ccz3kwljddnrhroozcix4gtqtxgrimz.png)
Step-by-step explanation:
Part 1) we have
![g=xc](https://img.qammunity.org/2020/formulas/mathematics/middle-school/vedf9r9e8jx7gmn10k2352esv54f5ta1v8.png)
solve for x
That means---> Isolate the variable x
Divide by c both sides
![(g)/(c)=(xc)/(c)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/l53fb83l4dyhvt6gh1w5vzmdyyy32u1lm1.png)
simplify
![x=(g)/(c)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/pyl698rkfip33vos6gdgox9b38xymid3tb.png)
Part 2) we have
![12ab=4](https://img.qammunity.org/2020/formulas/mathematics/middle-school/jjclcanb8f03f4suytko6maikftpbuikd8.png)
solve for a
That means---> Isolate the variable a
Divide by 12b both sides
![(12ab)/(12b)=(4)/(12b)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/v1i02yawnaahyjmhm1qqhx9bw0wal00zy9.png)
simplify
![a=(1)/(3b)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/mbr5pe4vrzotfhg0er4xbg49k1o4ner86w.png)
Part 3) we have
![am=n+p](https://img.qammunity.org/2020/formulas/mathematics/middle-school/wbrkq4yv8m4t8t01caxqn7i2qce2qndeo7.png)
solve for a
That means---> Isolate the variable a
Divide by m both sides
![(am)/(m)=(n+p)/(m)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/g676yegj099jafsx85dca3zcf1qyf1jd13.png)
simplify
![a=(n+p)/(m)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/jxc12tbf7e7p1qwjrsveaio8uxjkgtq4gt.png)
Part 4) we have
![g=x-c+y](https://img.qammunity.org/2020/formulas/mathematics/middle-school/oghros20y90g228bvx47k3me6t0tlbl7eq.png)
solve for x
That means---> Isolate the variable x
Subtract y both sides
![g-y=x-c+y-y](https://img.qammunity.org/2020/formulas/mathematics/middle-school/i3ofvhi47h85yxbn92skdnw6jt4malktw6.png)
![g-y=x-c](https://img.qammunity.org/2020/formulas/mathematics/middle-school/52w10jiyjaw6hz6kqecg2ipmcc423skfrg.png)
Adds c both sides
![g-y+c=x-c+c](https://img.qammunity.org/2020/formulas/mathematics/middle-school/q0q08napbykpp06f5q81hskcvlugyxx3g1.png)
![g-y+c=x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/69bd6g57v6e6pxlmowozci893dz04l9cfk.png)
rewrite
![x=g-y+c](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gocwxek6ydy26xyc4hz9w67v48d6x9a641.png)
Part 5) we have
![xm=x+z](https://img.qammunity.org/2020/formulas/mathematics/middle-school/n0sz3ihokvbnuz0dvfxpzgcq0sdsyu3okc.png)
solve for x
That means---> Isolate the variable x
Subtract x both sides
![xm-x=x+z-x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/faaqacn6nsaq00snckn77xi0jq62xr3s3f.png)
![xm-x=z](https://img.qammunity.org/2020/formulas/mathematics/middle-school/cf60knrkl1uikygln8k75bexx5fcqhja0g.png)
Factor x left side
![x(m-1)=z](https://img.qammunity.org/2020/formulas/mathematics/middle-school/1cfwts75s7pxowtk4wzyk5e0lslaen8ig6.png)
Divide by (m-1) both sides
![(x(m-1))/(m-1)=(z)/(m-1)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/9ybl8jzd760d62r8touc9sjf2zz3hvjsz0.png)
![x=(z)/(m-1)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/5knvjkms5sgjpxipdhuea7jvsswc3ef2uo.png)
Part 6) we have
![g=ca-b](https://img.qammunity.org/2020/formulas/mathematics/middle-school/aai6se6mtmbqmmguydbf4zklshav9ru4sm.png)
solve for a
That means---> Isolate the variable a
Adds b both sides
![g+b=ca-b+b](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ndsbofsqtzj4twf7fzgm315wmf36wdmbkb.png)
![g+b=ca](https://img.qammunity.org/2020/formulas/mathematics/middle-school/q02c9vtv87ajhrw5svc4c1x2e9my5t7jlm.png)
Divide by c both sides
![(g+b)/(c)=(ca)/(c)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/agrbvcsk3gyixphajmfotojp4w9vgllm7n.png)
![a=(g+b)/(c)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gph6mtetul72evcj4dltsxl7tqokvj1ukm.png)
Part 7) we have
![A=bh](https://img.qammunity.org/2020/formulas/mathematics/college/yuf6lcra082i9rwttsf9hghwp7q1fo1152.png)
solve for b
That means---> Isolate the variable b
Divide by h both sides
![(A)/(h)=(bh)/(h)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/8atymfezvbv932zj8mc8phsr0sh1hkcn4q.png)
simplify
![b=(A)/(h)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/hcnnecp13xm3jj6h00rmbw7lkq7bwe9397.png)
Part 8) we have
![P=2L+2W](https://img.qammunity.org/2020/formulas/mathematics/high-school/49zjv4bjqynhaj2o62lqqm1njyw4qc5tan.png)
solve for W
That means---> Isolate the variable W
Subtract 2L both sides
![P-2L=2L+2W-2L](https://img.qammunity.org/2020/formulas/mathematics/middle-school/wz1e75wgd0e3et77dv2r0lw2rgp3k6mf08.png)
simplify
![P-2L=2W](https://img.qammunity.org/2020/formulas/mathematics/middle-school/clxbsu7rqyndn4unvhpsi5koyxk6uw7ytq.png)
Divide by 2 both sides
![(P-2L)/(2)=(2W)/(2)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/jjmw45yfl4jk3p7hszmc85sccjdx1s9y3y.png)
simplify
![W=(P-2L)/(2)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/3x5fkmnw2zniz6eoykotziwj4koezet1cj.png)
![W=(P)/(2)-L](https://img.qammunity.org/2020/formulas/mathematics/middle-school/923x4t41dafmmqwk7nrx2c81k5mly9tbx6.png)
Part 9) we have
![Q=(c+d)/(2)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/9q9jes3wygr4kdhb67mkdadqkr6i7vbqt8.png)
solve for d
That means---> Isolate the variable d
Multiply by 2 both sides
![2Q=(2)(c+d)/(2)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/xvry9s3o3yy4d1409oridb5p918z0y5v8z.png)
simplify
![2Q=c+d](https://img.qammunity.org/2020/formulas/mathematics/middle-school/nfp7k16tne6fywddea6lrq11tdowzssmzr.png)
subtract c both sides
![2Q-c=c+d-c](https://img.qammunity.org/2020/formulas/mathematics/middle-school/mr74j6g5480n6cu23joo5n4fy05ioscq80.png)
![2Q-c=d](https://img.qammunity.org/2020/formulas/mathematics/middle-school/2hj0bq6lgh1g8cm9gb1wa0w0918vy0mjqr.png)
rewrite
![d=2Q-c](https://img.qammunity.org/2020/formulas/mathematics/middle-school/mdobzqai7mawngq62i7l2oknyhbxyw1khw.png)
Part 10) we have
![Q=3a+5ac](https://img.qammunity.org/2020/formulas/mathematics/middle-school/h4iunsyri7d0vtmb68265ipvxys4krdred.png)
solve for a
That means---> Isolate the variable a
Factor the variable a in the right side
![Q=a(3+5c)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/62xi8gxxi5m1zk1zifmsl7y31frcwnfkif.png)
Divide by (3+5c) both sides
![(Q)/(3+5c)=(a(3+5c))/(3+5c)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/pxvgap6miqhl71d5fay6imzmrhxa9p16v0.png)
simplify
![a=(Q)/(3+5c)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ryfldms93g94xoh017k25ijw3rtqpef2ce.png)
Part 11) we have
![I=(PN)/(RN+A)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/s8zg7uiccthz9iyhgaammgtqcbtsa5yqlq.png)
solve for N
That means---> Isolate the variable N
Multiply in cross
![I(RN+A)=PN](https://img.qammunity.org/2020/formulas/mathematics/middle-school/9v7avrox8714lunx84ltqklcltqga5j377.png)
Apply distributive property left side
![IRN+AI=PN](https://img.qammunity.org/2020/formulas/mathematics/middle-school/t9weyy7tsmuvv82sol00jdfczde2klb373.png)
subtract PN both sides
![IRN+AI-PN=PN-PN](https://img.qammunity.org/2020/formulas/mathematics/middle-school/xpobyd68dv5u69yzddiyecdedp910er53w.png)
![IRN+AI-PN=0](https://img.qammunity.org/2020/formulas/mathematics/middle-school/i4jvmb5j2vu3tzqcyb2e4iirp5l3eq5407.png)
subtract AI both sides
![IRN+AI-PN-AI=-AI](https://img.qammunity.org/2020/formulas/mathematics/middle-school/hyoxbtuijz5nveiecoa7f1v1z2f4o7t3ur.png)
![IRN-PN=-AI](https://img.qammunity.org/2020/formulas/mathematics/middle-school/jih2h5kq4x1lwtxwz01r6w2eig6wa194iw.png)
Factor N left side
![N(IR-P)=-AI](https://img.qammunity.org/2020/formulas/mathematics/middle-school/bthbb6as5w2xwb17dhp0eanxntwyo0mfu5.png)
Divide by (IR-P) both sides
![(N(IR-P))/(IR-P)=-(A)/(IR-P)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/2w07s31zystv8oy40rrvcn4cykv8uve9zw.png)
simplify
![N=-(A)/(IR-P)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/qtwm8ft6s192dr99shen6pz7vf3hgssi06.png)
![N=(A)/(P-IR)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/h91myfirnzk4nr8h3y0ymuc13xwqi70bom.png)
Part 12) we have
![P=a+b+c](https://img.qammunity.org/2020/formulas/mathematics/middle-school/oftjeyabl1g7s2iex4uvl56u76hn2q52m6.png)
solve for b
That means---> Isolate the variable b
subtract (a+c) both sides
![P-(a+c)=a+b+c-(a+c)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/y666dnfb691i207fx3tfvee7ialaiil18z.png)
simplify
![P-(a+c)=b](https://img.qammunity.org/2020/formulas/mathematics/middle-school/wrb49yjcvor4pwl9pbm3f86kxrg07mdm5w.png)
rewrite
![b=P-a-c](https://img.qammunity.org/2020/formulas/mathematics/middle-school/230ccz3kwljddnrhroozcix4gtqtxgrimz.png)