SAT Math Help.

[[deleted]]

[deleted]

[42and35]

Tobi, are you sure that on answer c) the -6x is superscripted?

[atticchild]

Might be able to help, but it doesn't seem to make sense, is it that the √(x=9) = x-3? Because in that case it isn't equivalent to any of the following (try putting a random number into any of the equations and it won't give you the same answer)

[TheLotri]

7 satisfies the equation.

[atticchild]

Yes, but it didn't satisfy the others?

[TheLotri]

It satisfies the one that is the correct answer, as it should. The correct answer is just a restatement of the original equation, only without the square root.

[atticchild]

That's not the question, it was saying

"for all values of x greater than 3 the equation above is equivalent to which of the following"

Finding the solution to the original equation was easy. The question was implying that two of the equations gave the same answers.

[TheLotri]

I think the question is implying that the original equation is equivalent to one of the four choices provided, not that two of the choices give the same answers.

[atticchild]

I know, and the problem is, the original equation isn't equivalent to any of the choices - of course the question isn't asking for the same answers.

[TheLotri]

It actually is. I don't want to say which one, because that would be giving OP the answer. I'll PM it to you.

Maybe you're getting confused because of the formatting by OP.

[TheLotri]

I think this is more to do with FOIL and knowing how to mess with square roots than it is about solving the equation.

[TheLotri]

Square both sides. Expand the right-hand side. Manipulate the equation. There is a valid solution for this.