Since you have y alone on one side of the equation......
Use substitution and plug in 1/2x-4 for y in the other equation.

Distribute

Combine like terms

Add 8 to both sides

Divide by 4
and 
Plug this value in for x

Simplify

Multiply everything by 8 and simplify

Divide.....

Your answers are:

Answer:
Thx for the points
Step-by-step explanation:
Hello, you would divide 10.3 by 0.6 to get 17.166 repeating. So y equals 17.166.
Answer:
$29.41
Step-by-step explanation:
You know the discount price is 25 and the original is unknown so call it x. The sale is 15% off and that means that the jeans are 85% of what they used to be since 100-15 is 85. Then you plug it into a formula of 25/x = 85/100 then you cross multiply to get 2500=85x and when you solve for x and round you get $29.41