Question

Use the Quadratic Formula to solve the equation x 2 − 23 = 10 x

Answer 1

x = 5+4√3 or 5–4√3

Explanation:

x² – 23 = 10x

x² – 10x –23 = 0

Using quadratic formula

a = 1, b = –10 and c = –23

x = –b ± (√b² – 4ac)/2a

–(–10) ± (√(-10)² – 4(1)(–23))/2(1)

=>10 ± (√100 + 92)/2

=> 10 ± (√192)/2

=> (10 ± 13.856)/2

x = (10 + 13.856)/2 or (10 – 13.856)/2

x = 11.828 or –1.928

x = 5+4√3 or 5–4√3