Answer:
Step-by-step explanation:
12 + 4c + c = c + 4
12 + 5c = c + 4
12 + 4c = 4
4c = -8
c =-2
Y - y1 = [-9-(-5)]/[(9-10] * (x - x1)
y - (-9) = [-9 + 5] / [-1] * (x - 9)
y + 9 = (-4) / (-1) * (x - 9)
y + 9 = 4(x - 9)
y + 9 = 4x - 36
y = 4x - 36 - 9
y = 4x - 45 This is the slope - intercept form.
y - 4x + 45 = 0 This is the standard form
180=15+85+(4x-20)
180-15-85=4x-20
80=4x-20
4x-20=80
4x=80+20
4x=100
x=100/4
x=25
Divide the circumference by pi (3.14) to get the diameter