Question

Solving quadratic equation using the completing the square method. (a).x²+20x-12=0​

Answer 1

`x = -10 + 4 \sqrt7 \ , \ x = -10 - 4 \sqrt7`

Explanation:

x²+20x-12=0

a = 1, b = 20, c = -12

`x = (-b \pm √(b^2 - 4ac))/(2x)`

`x = (-20 \pm √(448))/(2)\\\\x = (-20 \pm √(8 * 8 * 7))/(2)\\\\x = (-20 + 8√(7))/(2) \ , \ x = (-20 - 8 \sqrt7)/(2)\\\\x = (-10 + 4√(7))/(1) \ , \ x = (-10 - 4 \sqrt7)/(1)\\\\x = -10 + 4 \sqrt7 \ , \ x = -10 - 4 \sqrt7`