y = - 5
substitute the value of x = 4 into the equation and solve for y
- 12 + 9y = - 57 ( add 12 to both sides )
9y = - 45 ( divide both sides by 9 )
y =
= - 5
The three missing lengths are the left hypotenuse, x, the middle altitude, y, and the right hypotenuse, z.
9/y = y/16
y^2 = 9 * 16
y^2 = 144
y = 12
9^2 + 12^2 = x^2
x^2 = 225
x = 15
12^2 + 16^2 = z^2
z^2 = 400
z = 20
From left to right, the sides measure 15, 12, and 20 units.
180 - 124 = 56
4x = 180 - (56 + 60)
4x = 180 - 116
4x = 64
x = 16
answer
B. 16