Question

Multiply 5(5-x)(5+x). What is the product?

Answer 1

First we use a^2-b^2=(a-b)(a+b)

Here a =5 and b = x

5(5^2-x^2)

5(25-x^2)

Now multiply with 5

125- 5x^2

Answer 2

First mutiply the binomials: (5-x)(5+x)

5(25+5x-5x-x^2), and finally multiply the polynomial by five:

-5x^2+125