Question 729482

{{{21y^2+72y-48}}}.....first factor out {{{3}}}

{{{3(7y^2+24y-16)}}}.......write {{{24y}}} as {{{-4y +28y}}}

{{{3(7y^2-4y +28y-16)}}}....group

{{{3((7y^2-4y)+(28y-16))}}}

{{{3(y(7y-4)+4(7y-4))}}}

{{{3(y+4)(7y-4)}}}