Question 791213
{{{27x^3+343y^3 }}}


{{{(3x)^3+(7y)^3 }}}


{{{(3x+7y)((3x)^2-(3x)(7y)+(7y)^2) }}} Sum of cubes factoring rule


{{{(3x+7y)(9x^2-21xy+49y^2) }}}


So {{{27x^3+343y^3 }}} factors to {{{(3x+7y)(9x^2-21xy+49y^2) }}}