Answer:
[tex]x = 4[/tex]
[tex]x = - 7[/tex]
Step-by-step explanation:
[tex]x^2+3x-28 \\ x ^{2} + 7x - 4x - 28 \\ x(x + 7) - 4(x + 7) \\ (x - 4)(x + 7) \\ x - 4 = 0 \: \: \: or \: \: \: x + 7 = 0 \\ x = 4 \: \: \: \: \: \: \: \: \: \: or \: \: \: \: x = - 7[/tex]
