Chapter 4.2, Problem 5CFU

To determine

To solve: $x^2+8x-20=0$ by completing the square.

Answer to Problem 5CFU

  $x=2\text{ or }x=-10$

Explanation of Solution

Given information: $x^2+8x-20=0$

Calculation:

  $x^2+8x-20=0$, That is:

  ${\left(x+4\right)}^2=20+16=36$

Thus: $x+4=\pm 6$

Therefore: $x=6-4=2\text{ or }x=-6-4=-10$

  $x=2\text{ or }x=-10$