Carcass wrote:
If x is equal to the sum of the even integers from m to n, inclusive, where m and n are positive even integers, which of the following represents the value of x in terms of m and n?
A. (m+n2)(n−m2+1)
B. 3(m+n)
C. n2−m22
D. 6(m+n)
E. (m+n2)(n−m2)
For this question, it's pretty easy to test values.
Let's say m = 2 and n = 6
So, x = 2 + 4 + 6 = 12
So, we'll plug m = 2 and n = 6 to be chances choice to see which one yields a value of 12.
A.
(2+62)(6−22+1)=(4)(3)=12.
PERFECT!B.
3(2+6)=24. No good. We need an output of 12. Eliminate. C.
62−222=16. No good. We need an output of 12. Eliminate. D.
6(2+6)=48. No good. We need an output of 12. Eliminate. E.
(2+62)(6−22)=(4)(2)=8. No good. We need an output of 12. Eliminate.