dhlee922 wrote:
i'm still a little confused by the answer choices.
is it because the question stem equates to B=0 OR A=C
so for answer choice A, A doesnt have to equal C because the B equaling 0 will just make the whole expression 0
but then for answer choice B, since B=0 OR A=C, since 1 or the 3 groups in parentheses will be 0, it will make the whole expression 0, therefore B must be true?
is it because the question stem equates to B=0 OR A=C
so for answer choice A, A doesnt have to equal C because the B equaling 0 will just make the whole expression 0
but then for answer choice B, since B=0 OR A=C, since 1 or the 3 groups in parentheses will be 0, it will make the whole expression 0, therefore B must be true?
Yes, exactly. We know that or b=0 or a-c=0 ( or both) .
We can rewrite B as b(a-c)(a+c), and since at least one of the terms is 0, the whole expression is 0.