$$15 x ^ { 4 } + 6 x ^ { 3 } - 7 x ^ { 2 } + 11 x - 21 ) \div ( 3 x ^ { 2 } + 4 )$$
$15x^{4}+6x^{3}-7x^{2}+11x-21$
$60x^{3}+18x^{2}-14x+11$
