Question

What are the solutions of -x^2+4x=x-4

Answer 1

x = -1 and x = 4

Explanation:

Step 1: Get everything to one side of the equation so it's set equal to zero..

-x² + 4x = x - 4 becomes...

-x² + 3x + 4 = 0 (subtract x and add 4 to both sides)

x² - 3x - 4 = 0 (divide both sides by -1, we want the x² term to be positive)

(x - 4)(x + 1) = 0 (factor)

so

x - 4 = 0, then x = 4

and

x + 1 = 0, then x = -1