Algebra 2 help?! Evaluating Expressions!?

Question

4(2m-n) - 3(2m-n)

m= (-15)

n=(-18)

i have a hard time with these problems when it comes to adding these negative numbers! if you could help that be awesome! tips on adding and subtracting negative numbers would help!

Answer 1

it's easy

just plug everything in 4(-30+18) - 3(-30+18)

then solve the parenthesis 4(-12) - 3(-12)

and multiply through -48 + 36 = -12

so just remember these rules

- a negative times a negative equals a positive

- a positive time a negative equals a negative

- subtracting a negative is like adding a positive ( ie. 2- (-2) becomes 2+2)

- adding a negative is like subtracting ( ie 2 + (-2) becomes 2-2)

if you remember these you'll have no problems!