Question

10. If m and n are positive integers and

2x(5x+3y) = mx² + nxy, what is the value
of m-n?
(A) -4
(B) -1
(C) 1
(D) 4

Answer 1

D.)

Explanation:

1.) Expand the expression with distributive property. If we expand, we get 10x^2+6xy.

2.) Figure out m and n based on the expression. Since m is in front of the x^2, that means that m=10, and since n is in front of the xy, that means that n=6.
3.) Compute based on m and n. Since m is 10 and n is 6, m - n = 10 - 6 = 4. Therefore, D.) is the answer.