The difference of the square of a number and 8 is equal to 7 times that number. Find the positive solution.

Correct answer: x₁ = 8

Step-by-step explanation:

Given equation is:

x² - 8 = 7x ⇒ x² - 7x - 8 = 0 ⇒ x² - 8x + x - 8 = 0 ⇒ x · (x - 8) + (x - 8) = 0

(x - 8) · (x + 1) = 0 ⇒ x₁ = 8 or x₂ = - 1

we accept a positive solution

x₁ = 8

God is with you!