Answer:
[tex]x = - 6 \: \: \: \: or \: \: \: \: \: x = - 7[/tex]
Step-by-step explanation:
[tex] {x}^{2} + 13x + 42 = 0\\ {x}^{2} + 6x + 7x + 42 = 0 \\ {x}(x + 6) + 7(x + 6) = 0 \\ (x + 6)(x + 7) = 0 \\ x + 6 = 0 \: \: \: \: \: or \: \: \: \: \: \: x + 7 = 0 \\ x = - 6 \: \: \: \: or \: \: \: \: \: x = - 7[/tex]
