Question 958898

 {{{10r^4+30r^3+5r^2+15r }}}....factor out {{{5r}}}

 {{{5r(2r^3+6r^2+r+3) }}}....group

{{{5r((2r^3+6r^2)+(r+3)) }}}

{{{5r(2r^2(r+3)+(r+3)) }}}

{{{5r(r+3)(2r^2+1)}}}