Question

Alicia is solving a quadratic equation. She wants to find the value of x by taking the square root of both sides of the equation. Which equation allows her to do this? CLEAR CHECK x2+81x+18=54 x2−8x+24=17 x2+9x−24=25 x2+16x+64=36

Answer 1

d.) x2+16x+64=36

Explanation:

To find - Alicia is solving a quadratic equation. She wants to find the value of x by taking the square root of both sides of the equation. Which equation allows her to do this?

a.) x2+81x+18=54

b.) x2−8x+24=17

c.) x2+9x−24=25

d.) x2+16x+64=36

Proof -

The correct answer is - d.) x2+16x+64=36

x2+16x+64=36

⇒x² + 8x + 8x + 64 = 36

⇒x(x + 8) + 8(x + 8) = 36

⇒(x+8)(x+8) = 36

⇒(x+8)² = 36

Take square root both sides, we get

√(x+8)² = √36

⇒x + 8 = ± 6

⇒x + 8 = 6, x + 8 = -6

⇒x = 6 - 8 , x = -6 - 8

⇒x = -2, -14

So,

Equation (4) allows her to do the following thing she ants.