Meg hit $68. she bought four sets of watercolor paints. she now has $36. how much did each of the watercolor sets cost?

Kylie explained that (-4x+9)^2 will result in a difference of squares because (-4x+9)^2 (-4x+9)^2 =(-4x)^2+(9)^2=16x^2+81

Which fraction is not equivalent to 8/12 a. 2/3 b. 24/36 c. 4/10 d. 6/10

I’m really confused and need your assist me with this question i’ve never been taught