sqrt(x-27) + sqrt(x) = 9 solve for x... i tried squaring both sides to get the sqrts to go away but i still couldnt get the right answer. I need to know how to get to the final solution. FYI the answer is 36.
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Hello, Originally Posted by johntuan sqrt(x-27) + sqrt(x) = 9 solve for x... i tried squaring both sides to get the sqrts to go away but i still couldnt get the right answer. I need to know how to get to the final solution. FYI the answer is 36. Square it : Square again and solve the quadratic Recall that and (which makes )
Another way of doing it : Let and We have Now, multiply both sides by : So you have : Check if it is correct : Yay !
Originally Posted by Moo Another way of doing it : Let and We have Now, multiply both sides by : (x-27)-x=9(a-b) -27=9(a-b) So you have : Check if it is correct : Yay ! I'm probably being dumb once again, but where did those x's go?
Originally Posted by shinhidora I'm probably being dumb once again, but where did those x's go? And I kept (a-b) in the left side because we don't need to transform them into x.
Originally Posted by Moo Hello, Square it : Square again and solve the quadratic Recall that and (which makes ) Lookie here! You might like it this way, too. Pardon me, Moo. I just needed to post something. Haven't been on a lot today. Move the to the RHS. Square both sides. Collect terms. Square both sides again. Divide
Originally Posted by Moo And I kept (a-b) in the left side because we don't need to transform them into x. I'm so stupid... I read the as ... As I said, I was being dumb
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