What must be added to both sides in 4x² + 24x + 8 = 32 in order to complete the square?

16

Step-by-step explanation:

To solve a quadratic equation by using the completing the square method, the coefficient of the square term i.e x² must be one (1).

Therefore, we would have to first make the coefficient of x² to be equal to 1.

4x² + 24x + 8 = 32

We would simplify the equation;

4x² + 24x = 32 - 8

4x² + 24x = 24

Divide all through by 4;

x² + 8x = 24

The value to be added = (8/2)² = 4² = 16

x² + 8x + 16 = 8 + 16

x² + 4x + 4x + 16 = 24

x(x + 4) + 4(x + 4) = 24

(x + 4)² = 24

Taking the square root of both sides;

x + 4 = ± 4.9

x = -4 ± 4.9

x = -4 + 4.9 = 0.9

or

x = -4 - 4.9 = - 8.9

Therefore, 16 must be added to solve the quadratic equation by completing the square method.