Question

PLS ANSWER ASAP!!!!!! To solve x^2−8x=10 by completing the square, what should be added to both sides? A. 64 B. 16 C. 8 D. −16

Answer 1

Answer:

B.  16

Step-by-step explanation:

x² − 8x = 10

x² − 8x + (-4)² = 10 + (-4)²

x² − 8x + 16 = 10 + 16 --------- added 16 to both sides.

to finish the equation..

x² − 8x + 16 = 26

(x - 4)² = 26

$\sqrt(x - 4)^2 = \sqrt{26}$

x = $\sqrt{26} + 4$

x = $4 - \sqrt{26}$

Answer 2

Answer:

$\Huge \boxed{\mathrm{B. \ 16}}$

$\rule[225]{225}{2}$

Step-by-step explanation:

$x^2-8x=10$

The equation is in the form ax² + bx = -c. The value of b in the equation is -8.

To complete the square, we need to add (b/2)² = (-8/2)² =  -4² = 16 to both sides.

$x^2-8x+16=26$

Factoring left side of the equation.

$(x-4)^2 =26$

Taking the square root of both sides.

$x-4=\pm\sqrt{26}$

Adding 4 to both sides.

$x=4\pm\sqrt{26}$

$\rule[225]{225}{2}$