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

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

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

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√(26)`

Adding 4 to both sides.

`x=4\pm√(26)`

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

Answer 2

B. 16

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 = √(26)`

x =
`√(26) + 4`

x =
`4 - √(26)`