`a)-2x³y(-1/2xy²)^2(-2(1)/2x²y³(a-1))`
`=-2x³y. 1/4x²y^4(-5/2x²y³(a-1))`
`=[(-2). 1/4 .(-5)/2(a-1)].(x³.x².x²).(y.y^4 .y³)`
`=5/4(a-1)x^7 y^8`
-Hệ số:`5/4(a-1)`
-Phần biến:`x^7y^8`
-Bậc:`15(7+8=15)`
`b)(-3ax²y²)(-axy²)^3(-2xy²)`
`=(-3ax²y²)(-a³x³y^6)(-2xy²)`
`=[(-3).(-2)].[a.(-a³)].(x².x³.x).(y².y^6 .y²)`
`=-6a^4x^6y^10`
-Hệ số:`-6a^4`
-Phần biến:`x^6y^10`
-Bậc:`16(6+10=16)`