- #1
TechnocratX
- 3
- 0
Solve |x-3|^2 - 4|x-3|=12
The solution to this equation is -3, 9. But I'm not sure on the working.
There is a hint to let u=|x-3|
So I worked it out the following way.
u^2 -4u = 12
u^2 -4u -12 = 0
(u + 2)(u - 6)=0
u /= -2 and u /= 6
|x-3|=-2 (no solution)
|x-3|= 6, x = 9
Now to work out negative part.
u^2 -4u = -12
u^2 -4u + 12 =0
(no real roots)
So would I use |x-3|=-6, x = -3
The solution to this equation is -3, 9. But I'm not sure on the working.
There is a hint to let u=|x-3|
So I worked it out the following way.
u^2 -4u = 12
u^2 -4u -12 = 0
(u + 2)(u - 6)=0
u /= -2 and u /= 6
|x-3|=-2 (no solution)
|x-3|= 6, x = 9
Now to work out negative part.
u^2 -4u = -12
u^2 -4u + 12 =0
(no real roots)
So would I use |x-3|=-6, x = -3