Solve by factoring ... m^2 + 8m + 7 = 0

In order to solve an equation by factoring, it should be that the equation is equal to zero.

m^2 + 8m + 7 = 0

For this case we have, to do completing the square in order to factor this equation.

m^2 + 8m = - 7

m^2 + 8m + 16 = - 7 + 16

(m+4) (m+4) = 9

(m+4) ^2 = 9

Take the square root of both sides,

m+4 = 3

m = - 1