So i've gotten 3 different answers on my question "mark is 15 years younger than ashley. the sum if their ages is 55. write a system of equations to determine mark (m) age and ashley (a) age"and i just want another opinion on how to write both equation and how to solve them ! the answer i got most recently was "a-m=55 and a-15=55" which sounds right but i don't know how i'd solve for ashley or marks age