Question

What shows 23^2-17^2 being evaluated using the difference of perfect squares method

Answer 1

23^2 - 17^2
= (23-17)(23+17)
=  6 * 40
= 240

Answer 2

Remember
a²-b²=(a-b)(a+b)

so
23²-17²=(23-17)(23+17)=(6)(40)=240