(x+7)(x+7) is the same as (x+7)^2
Using distributive property:
(x^2+7x+7x+49)
x^2+14x+49 is your answer.
A shorter way to do it if you know this:
If you know the general form ax^2+bx+c, to go from (x+7)^2 to that form is by knowing that b will be double 7, and that c will automatically be 7 squared.
Then, you know that it just goes to x^2+14x+49
