Answer:
[tex]x = - 4\: or \: x = 9[/tex]
Step-by-step explanation:
make one side equal to zero:
[tex] {x}^{2} - 5x - 36 = 0[/tex]
find two factors that multiply to -36 and add to -5 (-9 & 4)
[tex] {x }^{2} - 9x + 4x - 36 = 0[/tex]
factorise
[tex]x(x - 9) + 4(x - 9) = 0[/tex]
[tex](x + 4)(x - 9) = 0[/tex]
solve for x
[tex]x = - 4 \: or \: x = 9[/tex]
