Hey there! :D
Let's start with the first one.
1.) 3b-2=13
You need to balance the equation and do the opposite to the other side. To get rid of the 2, we would have to add 2 to both sides.
3b-2(+2)=13(+2)
3b=15
Divide both sides by 3. (the inverse of multiplication)
b=5
Now, check it by plugging it in.
3b-2=15
3(5)-2=13
15-2=13
13=13 <== this works
Let's try another:
2.) 4a+2-a+10= 33
Combine like terms.
4a-a=3a
2+10=12
3a+12= 33
Subtract 12 on both sides.
3a=21
Divide both sides by 3.
a=7
Check our work:
4a+2-a+10=33
4(7)+2-7+10=33
28+2-7+10=33
30-7+10=33
23+10=33
33=33 <=== this works
Let's try one more, and you can try the last one.
3.) 2(w-3)+6w=10
Distribute. (multiply 2 to w and -3)
2*w=2w
2*-3=-6
2w-6+6w=10
Combine like terms.
8w-6=10
Add 6 to both sides.
8w=16
Divide both sides by 8.
w=2
Check your work:
2(w-3)+6w=10
2(2-3)+6(2)=10
4-6+12=10
-2+12=10
10=10 <== this works
I hope this helps! Have a great day.
~kaikers