Answer:
x - 
Step-by-step explanation:
y = x + 10/7
x = y + 10/7
x = y + 10/7
x - 10/7 = y
y = x - 10/7
x - 
We are given with three lengths of a triangle expressed in terms and variables: (3x – 4) feet, (x^2 – 1) feet, and (2x^2 – 15) feet. The perimeter of the triangle is equal to the sum of the three sides of the triangle. In this case, the sum is 3x^2 + 3x -20. When x is equal to 4, we substitute <span>3*16 + 3*4 -20 equal to 40 feet.</span>
ummm I think I know but I don't at the same time take away 40 from 112 and theres you answer♥.