Question 209289
Factor completely:
{{{x^2+12x-28}}}
The factors will have the form:
{{{(x+m)(x+n)}}} where {{{m*n = -28}}} and {{{m+n = 12}}}
Let's do the -28 factors first:
{{{-28 = -1*18}}} 
{{{-28 = 1*(-28)}}}
{{{-28 = -2*14}}}
{{{-28 = 2*(-14)}}}
{{{-28 = -4*7}}}
{{{-28 = 4*(-7)}}}
Now which of the pair of factors, when added, gives you 12?
How about -2 and 14?, so m = -2 and n = 14, thus...
{{{highlight(x^2+12x-28 = (x-2)(x+14))}}}