Question

Please Help!

(3w+5)^2

Answer 1

(x+y)^2 = x^2 + 2xy + y^2

Answer 2

so would that be the FOIL method?

Answer 3

The formula in my first reply is an algebraic identity.
You need the foil method only when you want to multiply out (3w+5)(3w+5).

Either way you will get the same answer after simplification.
But the identity method will be faster.

Answer 4

if it wont take too much time, can you tell me what the identity method is?

Answer 5

(x+y)^2 = x^2 + 2xy + y^2
The identity says: square the first term + 2 * (first term) * (second term) + square the second term.
(3w + 5)^2 = (3w)^2 + 2 * 3w * 5 + (5)^2 = ?

Answer 6

ok thanks

Answer 7

so i got 9w+30w+25

Answer 8

(3w + 5)^2 = (3w)^2 + 2 * 3w * 5 + (5)^2 = 9w^2 + 30w + 25

Answer 9

ok thanks so much :D

Answer 10

You are welcome.

If you FOIL it and simplify you will get the same answer:
(3w+5)^2 = (3w+5) * (3w+5) = (3w)(3w) + (3w)(5) + (5)(3w) + (5)(5) =
9w^2 + 15w + 15w + 25 = 9w^2 + 30w + 25.