Question

Let f(x) = 8x^2 + 8x − 3. Find and simplify the following. f(a + 3)

Answer 1

Do you need just the answer or an explanation? I can give both. Which do you prefer?

Answer 2

both please

Answer 3

??

Answer 4

I'm trying

Answer 5

You just take the numbers and everywhere you see x you plug in (a+3)
So it'd give you 8(a+3)^2+8(a+3)-3
Which ends up giving you 8x^2+56x+93 in the end

Answer 6

how did you get 56x

Answer 7

Because 8(a+3)^2 + 8(a+3)-3= 8a^2 +48a+72+8a+21,
So I'm getting the 56a from the 48a+8a

Answer 8

i am still not understanding where you are getting 48a from? because if its 8(a+3)^2 shouldnt it be 8a^2+17 ???

Answer 9

I'm not understanding where you're getting that from. It would be 8(a+3)(a+3) then you would FOIL the (a+3)s and it would give you (a^2+6a+9) Then you would multiply that by 8 giving you 8a^2+48a+72

Answer 10

ok i am getting it now, thank you!

Answer 11

Welcome!