Question 489990


{{{ x^2-3x-28}}}....replace {{{-3x}}} with {{{4x-7x}}} (these numbers are factors of 28)

{{{ x^2+4x-7x-28}}}...group


{{{( x^2+4x)-(7x+28)}}}


{{{x( x+4)-7(x+4)}}}


{{{(x-7)(x+4)}}}