Question 18026
(x+7)(x+3) is a quadratic factored
you need to use the foil method
F-Firsts (x times x)
O-Outsides (x times 3)
I-Insides (7 times x)
L-Lasts (7 times 3)
x times x is {{{x^2}}}
x times 3 is 3x
7 times x is 7x
7 times 3 is 21
Now, you have to add them up, you get:
{{{x^2+3x+7x+21}}}
after combining like terms, you get:
{{{x^2+10x+21}}}