What expression is equivalent to m + 0.47m – 0.4?

For the given quadratic equation convert into vertex form, find the vertex and find the value for x=6 y=-2x^2+2x+2

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

Factor the expression using the gcf. the expression 21m−49n factored using the gcf