For what values of x is x2-36=5x true?

x = - 4, x = 9

Step-by-step explanation:

Given

x² - 36 = 5x ( subtract 5x from both sides )

x² - 5x - 36 = 0 ← in standard form

Consider the factors of the constant term (- 36) which sum to give the coefficient of the x- term (- 5)

The factors are - 9 and + 4, since

- 9 × 4 = - 36 and - 9 + 4 = - 5, thus

(x - 9)(x + 4) = 0

Equate each factor to zero and solve for x

x + 4 = 0 ⇒ x = - 4

x - 9 = 0 ⇒ x = 9

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18