Question

How do you simplify by multiplying `(x+10)^2`?

Answer 1

it's easy. As suggested, I first want to show where `(a+b)^2` is equal to.
`(a+b)^2 = (a+b)* (a+b) = a*(a+b)+b*(a+b) = a*a+b*a+a*b+b*b = a^2+2ab+b^2`

Now we can easily fill in x and 10:
`(x+10)^2=x^2+2*x*10+10^2 = x^2+20x+100`