How do i do them ? i don't know if i started them right.

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

Points a, b, and c form a triangle. complete the statements to prove that the sum of the interior angles of triangle abc is 180

In a class, there are 12 girls. if the ratio of boys to girls is 5: 4 how many boys are there in the class