Answer:
step 1: x+50+4x=90
the angle of a right-angled triangle is 90 degrees, therefore if we add everything together ,we could work out what x is.
step 2: x+50+4x=90
x+4x=50
5x=50
x=10
then you solve the equation, x is 10
Step-by-step explanation:
y = 8x² + 8x - 96
y = 8(x² + x - 12)
y = 8(x + 4)(x - 3)
When y = 0, 8(x + 4)(x - 3) = 0.
=> x = -4 or x = 3. (B)