Can you Factorise x2 - 100?

Answer 1

-98

Answer 2

This is what we call a "difference of squares". Whenever you see a perfect square subtracted from another perfect square, this statement will be true:

a2 - b2 = (a + b)(a - b)

In this case, our perfect squares are x2 and one hundred, so this can be factored out as:

(x + 10)(x - 10)