{{{((5x-5y)/(x^2+6xy-16y^2))/((5x - 10y)/(x^2 + 10xy + 16y^2))}}} Start with the given expression {{{((5x-5y)/(x^2+6xy-16y^2))*((x^2 + 10xy + 16y^2)/(5x - 10y))}}} Multiply the first fraction by the reciprocal of the second fraction {{{(5(x-y)/(x^2+6xy-16y^2))*((x^2 + 10xy + 16y^2)/(5x - 10y))}}} Factor out 5 out of the first numerator {{{(5(x-y)/(x+8y)(x-2y))*((x^2 + 10xy + 16y^2)/(5x - 10y))}}} Factor the first denominator {{{(5(x-y)/(x+8y)(x-2y))*((x+8y)(x+2y)/(5x - 10y))}}} Factor the second numerator {{{(5(x-y)/(x+8y)(x-2y))*((x+8y)(x+2y)/5(x - 2y))}}} Factor the second denominator {{{(cross(5)(x-y)/cross((x+8y))(x-2y))*(cross((x+8y))(x+2y)/cross(5)(x - 2y))}}} Cancel out like terms {{{((x-y)/(x-2y))*((x+2y)/(x - 2y))}}} Simplify {{{(x-y)(x+2y)/(x-2y)^2}}} Multiply the two fractions