Sergey is solving 5x2 + 20x – 7 = 0. which steps could he use to solve the quadratic equation? check all that apply.
1) 5(x2 + 4x + 4) = –7 + 20
2) x + 2 =
3) 5(x2 + 4x) = 7
4) 5(x2 + 4x + 4) = 7 + 20
5) 5(x2 + 4x) = –7
6) x + 2 =

step-by-step explanation:

we have that

group terms that contain the same variable, and move the constant to the opposite side of the equation

factor the leading coefficient

complete the square. remember to balance the equation by adding the same constants to each side

rewrite as perfect squares

square root both sides