If m, k, x, and y are positive numbers, is mx+ky>kx+my?

[KarlS319]

If m, k, x, and y are positive numbers, is mx + ky > kx + my ?

(1) m > k

(2) x > y

I rearranged the equation as follows..... is mx - my > kx - ky ? I was trying to think through it intuitively but falsely assumed that the values of x and y didn't matter since they mirrored each other so proceeded through the statements with m > k ? in mind which lead me to A and not C. I tested a number of cases via spreadsheet (found it challenging to test cases with four variables) and get that the values of m, k, x, and y all matter i.e. you need both (1) and (2) to answer definitively yes or no.

Question: how do you proceed through this one efficiently? Is there anyway to rearrange the original equation into a more intuitive format or test cases in a simple manner?

[Sage Pearce-Higgins]

Again, if this is from a paid for resource, we'll have to remove the question.

Testing cases in inequalities with multiple variables can be tough, since there are so many possibilities. I'd recommend the following rephrase:
mx + ky > kx + my ?
mx - my > kx -ky ?
m(x - y) > k(x - y) ?
This is only true if m>k and if (x - y) is positive.

[KarlS319]

This is not from a paid resource. Thanks for the explanation.

[Sage Pearce-Higgins]

You're welcome.