Example 2

Using FOIL to find a product quickly

Find each product. Write down only the answer.

a) (x + 3)(x + 4)

a) (x + 3)(x + 4) = x2 + 7x + 12 Combine like terms: 3x + 4x = 7x.

I don't understand this. I get how they got 3x+4x=7x but i do not understand how that is equal to x2 + 7x + 12?

Using foil you get x2 + 7x + 12 if you combine like terms you get 3x + 4x = 7x I can't wrap my head around why these are equivelent statements.