Question

Three students used factoring to solve a quadratic equation.

Answer 1

Answer:

The solution was solved correctly by Keith

The solutions of the equation are x=-5,x=-12

Step-by-step explanation:

we have

$x^{2}+17x+72=12$

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

$x^{2}+17x=12-72$

$x^{2}+17x=-60$

Complete the square. Remember to balance the equation by adding the same constants to each side.

$x^{2}+17x+8.5^{2} =-60+8.5^{2}$

$x^{2}+17x+72.25 =12.25$

Rewrite as perfect squares

$(x+8.5)^{2}=12.25$

square root both sides

$(x+8.5)=(+/-)3.5$

$x=-8.5(+/-)3.5$

$x=-8.5(+)3.5=-5$

$x=-8.5(-)3.5=-12$

The solution was solved correctly by Keith

The solutions of the equation are x=-5,x=-12