Question

Which shows a difference of squares?

10y^2 – 4x^2

16y^2 – x^2

8x^2 – 40x + 25

64x^2 – 48x + 9

Answer 1

Hello,

1) (√10 y)²-(2x)²
2) (4y)²-x²
3)8x²-40x+25=8(x²-5x)+25
=8(x²-2*5/2*x+25/4)+25-8*25/4
=8(x-5/2)²-25
=8(2x-5)² /4 -25
=[√2*(2x-5)]²-5²

4)
64x²-48x+9=(8x-3)²-0²