Asked by claire

Dennis says that (2x-7)^2=(7-2x)^2.Do you agree with Dennis?Explain

Answer please steve
Answered by Steve
huh? I already told you one thing to try. If they are equal, they must be equal for <b>all</b> values of x.

So, is it true if x=2?
Answered by Steve
Oops. I guess you mistyped it before. I see it is different now.

So, you know that u^2 = (-u)^2, right?

so what if u = 2x-7 ?
Answered by claire
That is x
Answered by Steve
huh? what does that mean? "That is x" ? ?

If u = 2x-7, then
(2x-7)^2 = (-(2x-7))^2 = (7-2x)^2