计算:1) 4y*(-2xy²)
计算 2xy[4x²y²-3y(xy+x²y)-xy²]
合并同类项并计算 -3[y-(3x²-3xy)]-[y+2(4x²-4xy)]其中,x=3,y=1/
计算(1/2xy+y²+1)+(x²-1/2xy-2y²-1)
1、计算:①(4X²-5xy)-(1/3y²+2x²)+2(5xy-1/4y²-
计算(-3/2xy)(2/3x²-4xy²)+4/3y(3/4x³-1/2x³y
计算 (x²+2xy+y²)(x²-xy+y²)²
计算:(-7x²y)(2x²y-3xy³+xy)
计算(3x^3y-x^2y+1/2xy)÷(-1/2xy)
计算 (_2x²y³)²×(4xy²)-¹×(2x²y)
计算:(3x³y)²*(4y)²÷(2xy)³
计算;(xy-x²)÷x²-2xy+y²/xy · x-y/x²
分式计算:(x²+2xy+y²)/(x²y+xy)*y/(x+y)