Question

Find the number of real number solutions for the equation. x2 + 9x + 20 = 0

Answer 1

$x^2 + 9x + 20 = 0 \\ x^2+4x+5x+20=0\\ x(x+4)+5(x+4)=0\\ (x+5)(x+4)=0\\ x=-5 \vee x=-4$