# can someone please check if im right : math

posted by
**alejandra** on
.

4(3x+7)

is this the equivalent expression : 12x+28

Yes it is, that' using the distributive property.

ok. how do i get the opposite of an expression example : -10t+21

The opposite? Do you mean the negative or additive inverse of the expression? If so then multiply it by -1. Thus

(-1)(-10t+21) is the opposite of your expression.

You already know the distributive propery, so apply it here.

its because the question that i have it says give the opposite of each expression and one of them is -10t+21

is the opposite of -10t+21= 11t or 31t

No. If you meant the negative of -10t+21 then it's

(-1)(-10t+21)=(-1)(-10t) + (-1)*21

That's why I asked what you meant about the opposite.

its because i don't understand neither the question just says give the opposite of each expression

its because i don't understand neither the question just says give the opposite of each expression

ok, no problem. Just read what's written, check the book for examples and don't omit important details when posting, otherwise I spend time guessing which doesn't help either of us. That's all :)

Yes Its Correct