hey, i need help for this question... i just don get it.

Question

this is what the problem says, Are 5n + 9 + n and 3(2n +9) equivalent expressions? use substitution to prove your answer. I really need help... please

Answer 1

Pick a few different numbers for "n" and substitute into the two expressions and see if they equal the same thing.

So maybe try like n = -1, n = 0, and n = 2. If the two expressions equal the same answer when you plug in these numbers for "n", then they are equivalent expressions. If the two expressions give you different answers after plugging in for "n", then they are NOT equivalent expressions.

Answer 2

All we need to do here is substitute ANY NUMBER fo n and see if they work out the same.

Let's use 2 because it's easy.

5(2) + 9 + 2 = 10 + 9 + 2 = 21

we'll ALSO substitute 2 in the OTHER expression

3(2(2)+9) = 3(4+9) = 3(13) = 39

so since ONE equaled 21 and the OTHER 39 they are NOT equivalent.

Can I help with anything else?

Jo