Question 482393
Simplifying by collecting like terms: I have a math problem that reads: Subtract the sum of -3m and -6p from their difference. My teacher says the answer is -12p. I am having trouble understanding the wording and setting up the problem. Can you help me solve this?
Thank you!


Subtract the sum of -3m and  - 6p


the sum of - 3m and - 6p ------> - 3m + (- 6p) -------> - 3m - 6p


Their difference: - 3m - (- 6p) -------> - 3m + 6p


Since you're told to subtract the sum (- 3m - 6p) from the difference (- 3m + 6p), then we'll have: - 3m + 6p - (- 3m - 6p), which gives us: - 3m + 6p + 3m + 6p = - 3m + 3m + 6p + 6p = {{{highlight(12p)}}}


I agree with the other two tutors in that the teacher is incorrect, as the answer is in fact: {{{highlight_green(12p)}}}