Question 103805
{{{x^2+3xy-10y^2}}} Start with the given expression


Now what two numbers multiply to -10 but add to 3? These two numbers are 5 and -2. So {{{x^2+3xy-10y^2}}} breaks down to 



{{{x^2+5xy-2xy-10y^2}}} Replace 3xy with 5xy-2xy



{{{(x^2+5xy)+(-2xy-10y^2)}}} Group like terms



{{{x(x+5y)-2y(x+5y)}}} Factor out the GCF out of each group



{{{(x-2y)(x+5y)}}} Combine like terms




So {{{x^2+3xy-10y^2}}} factors to {{{(x-2y)(x+5y)}}}