Đáp án:
a/2x²y-4xy²+6xy
=2xy.x-2xy.2y+2xy.3
=2xy(x-2y+3)
b/ 4x³y²-8x²y³+$2x^{4}$y
= 2x²y.2xy-2x²y.2y²+2x²y.x²
=2x²y(2xy-2y²+x²)
c/ 9x²y³-$3x^{4}$y²-6x³y²+18x$y^{4}$
= 3xy².3xy-3xy².x³-3xy².2x²+3xy².6y²
=3xy²(3xy-x³-2x²+6y²)
d/ 7x²y²-21xy²z+7xyz-14xy
=7xy.xy-7xy.3yz+7xy.z-7xy.2
=7xy(xy-3yz+z-2)
e/ a³x²y-$\frac{5}{2}$$a^{3}$$x^{4}$+$\frac{3}{2}$$a^{4}$x²y
=a³x².y-a³x².$\frac{5}{2}$x²+a³x².$\frac{3}{2}$ay
=a³x²(y-$\frac{5}{2}$x²+$\frac{3}{2}$ay)