Asked by muffy

Does this:
sqrt 3x-4=(x-4)^2-3

Multiply out to:

x^4-16x^3+90x^2-111x+173

Once I know it is multiplied out right then I can continue. Thanks


Answered by Steph
i got 3x^2-16x+16
Answered by Reiny
no
first of all, you don't have an equation as your answer.

√(3x-4)=(x-4)^2-3
square both sides
3x-4 = (x-4)^4 - 6(x-4)^2 + 9
3x - 4 = x^4 - 16x^3 + 96x^2 - 256x + 256 - 6x^2 + 48x - 96 + 9
x^4 - 16x^3 + 102x^2 - 211x + 166 = 0

Answered by muffy
Oh thanks didn't see this post.

I realized I needed to make it equal zero. I keep getting 90 x^2 instead of 102 and 173 instead of 166.

Why do they make this so hard?
Answered by Reiny
the difficulty is that you have to square the whole side, not just each term.

I agree with you, that is a hard question at your level.
Solving the final equation would be a nightmare.
Answered by muffy
I'm looking at your solution and I can't figure out where that -6 came from.