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# Help solving equation? watch

1. Hi there, could somebody help me solve this equation?

Thanks
2. Multiply through by . If it helps, make the substitution -- it's a quadratic in disguise.
3. Ok so this is what I have so far, but I still don't really understand how to solve it.

Could somebody tell me what to do next?
Thanks
4. (Original post by vivaespana)
Ok so this is what I have so far, but I still don't really understand how to solve it.

Could somebody tell me what to do next?
Thanks
U^2 = 4U + 12
U^2-4U-12 = 0
5. (Original post by vivaespana)
Ok so this is what I have so far, but I still don't really understand how to solve it.

Could somebody tell me what to do next?
Thanks
Multiply both sides by as nuodai said. So you get:

Expand out the RHS, collect all terms on one side and solve the quadratic. Then note that , so set your solutions for U equal to and solve for t. REMEMBER, CANNOT BE NEGATIVE (assuming t is real, which I'm guessing it is judging by the difficulty of the question).
6. (Original post by IAmTheChosenOne)
U^2 = 4U + 12
U^2-4U-12 = 0
factorise this to get (u + 2)(u - 6) = 0, so u = -2 or u = 6?
7. multiply through so you get U^2 = 4U + 12
then U^2 - 4U -12 = 0
then (U -6)(U + 2) = 0
so U = 6, or U = -2
8. (Original post by vivaespana)
Ok so this is what I have so far, but I still don't really understand how to solve it.

Could somebody tell me what to do next?
Thanks
Multiply by U to get a quadratic.

Put in the form ax^2 + bx + c = 0.

Solve by factorisation.

U = root (t)

Find t by squaring both sides.

9. Thanks guys I understand it now

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