Answer:
4
Step-by-step explanation:
x=9/4
we have:
(4x + 15) = 24
4x=24-15
4x=9
finally: x=9/4
subsitute x = 6 into the lengths
3(6) -7
18 - 7
11cm
(6) + 5
therefore it is a square when x = 6 because the sides are all equal
-4x^2-28x
Distribute
-4x(x) and -4x(-7)
-4x^2 and -28x
