4 . B
The easiest way to find the answer to this question is to check the answer
choices, starting with the smallest, until you find one that meets the
given conditions. A multiple of 2 and 5 is a multiple of 10, so already you
know that the answer is (A), (B), or (C). Starting with (A), divide each by 7
until you find one that leaves a remainder of 2. (A) 20 divided by 7 is 2
with a remainder of 6—that’s not it. (B) 30 divided by 7 is 4 with a
remainder of 2—that’s it.5 . E
The two rectangles have the same height, so if CDEF has twice the area of
ABCF, then the base of CDEF is twice the base of ABCF. The longer base is
given as 2x + 2, so the shorter base is half that, or x + 1. You’re looking for
AE, which is the sum of the lengths of the bases:
6 . B
The second equation expresses y^2 in terms of x, so you can substitute
that expression for y^2 in the first equation and solve for x: