Use completing the square to solve for x in the equation (x minus 12) (x + 4) = 9. x = –1 or 15 x = 1 or 7 x = 4 plus-or-minus StartRoot 41 EndRoot x = 4 plus-or-minus StartRoot 73 EndRoot

Mathematics · Middle School · Tue Nov 03 2020

Answered on

Given the equation:

( x - 12)  ( x + 4) =9

Solve for x.

Solution:

In order to solve for x, we simply needed to equate the factors to 0.

x - 12 = 0

x + 4 = 0

Now we need to transpose -12 and 4 to the opposite sides of the equation, hence it must be taken to note that in transposing a number, the sign changes.

x = 12

x = -4

Final answer:

x = 12

x = -4