Question

What are the solutions of the quadratic equation (x – 8)2 – 13(x – 8) + 30 = 0? Use u substitution to solve. x = –11 and x = –18 x = –2 and x = 5 x = 2 and x = –5 x = 11 and x = 18

Answer 1

The answer is D on EDGE 2020

Explanation:

Answer 2

x=11 and x=18

Explanation:

The given quadratic equation is;

`(x-8)^2-13(x-8)+30=0`

Let u=(x-8)

`u^2-13u+30=0`

Split the middle term;

`u^2-10u-3u+30=0`

Factor by grouping

`u(u-10)-3(u-10)=0`

`(u-10)(u-3)=0`

We have either u=10 or u=3

This implies that;

x-8=10 or x-8=3

x=10+8 or x=3+8

x=18 or x=11