Answer:
The amount of money the oldest sister earns per job is $120
The amount of money the middle sister earns per job is $80
The amount of money the youngest sister earns per job is $60
Explanation:
Let
x -----> amount of money the oldest sister earns per job
y -----> amount of money the middle sister earns per job
z -----> amount of money the youngest sister earns per job
we know that
50 percent more means ----> 100%+50%=150%=150/100=1.50
50 percent less means ----> 100%-50%=50%=50/100=0.50
so
-----> equation A
----->
---->
-----> equation B
-----> equation C
substitute equation B and equation C in equation A and solve for x
![x+(2/3)x+0.50x=260](https://img.qammunity.org/2020/formulas/mathematics/middle-school/9sqpdz4fdifvqzwhvrsoki3btq8x5nkce4.png)
Multiply by 6 both sides to remove the fraction
![(6x+4x+3x)=(6)260](https://img.qammunity.org/2020/formulas/mathematics/middle-school/jdo6vo3phxbdnnj91rfaplezhm7lahutmy.png)
![13x=1,560\\x=120](https://img.qammunity.org/2020/formulas/mathematics/middle-school/qrpxzw9ib8bv1twh1mor8g8ah05bt96uc0.png)
Find the value of y
----->
![y=(2/3)120=80](https://img.qammunity.org/2020/formulas/mathematics/middle-school/uq3rzpjw9y71yerk8afz4pxtgsakr4yzik.png)
Find the value of z
---->
![z=0.50(120)=60](https://img.qammunity.org/2020/formulas/mathematics/middle-school/200w0jjm6l6vg6ek4sxpt77fggspypbl71.png)
therefore
The amount of money the oldest sister earns per job is $120
The amount of money the middle sister earns per job is $80
The amount of money the youngest sister earns per job is $60