Question 9358
when you have 2 symbols together like here, {{{65x-(-12x)}}}, there are rules that help to simplify. I have written a Lesson on this website that explains these very simple rules (but to be honest, rather difficult to explain why, in a meaningful way).


Anyway - and - can be thought of as + so we get {{{65x + 12x}}} which in turn is 77x


jon.