Question

Consider the equation:24 = x^2 - 4x + 31) Rewrite the equation by completing the square.Your equation should look like (x + c)^2 = d or (x – c)^2 = d.[ ]2) What are the solutions to the equation?Choose 1 answer:A) x=2 ± 5B) x = -2 ± √5C) x = 2 ± √5D) x = -2 ± √5

Answer 1

(x - 2)² = 25

Step-by-step explanation:

24 = x² - 4x + 3

rewritting:

x² - 4x = 24 - 3

x² - 4x = 21

using the completing the square:

coefficient of x = -4

square half the coefficient of x = (-4/2)² = (-2)²

Add the square half the cofficient of x to both sides of the equation

x² - 4x + (-2)² = 21 + (-2)²

taking out -4x:

(x - 2)² = 21 + 4

(x - 2)² = 25

The equation above is in the form (x + c)^2 = d or (x – c)^2 = d