[(xy-2)(-xy-2)-4(xy-1)^2]除以(-xy),其中x=20,y=-25分之1

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[(xy-2)(-xy-2)-4(xy-1)^2]除以(-xy),其中x=20,y=-25分之1
[(xy-2)(-xy-2)-4(xy-1)^2]除以(-xy),其中x=20,y=-25分之1

[(xy-2)(-xy-2)-4(xy-1)^2]除以(-xy),其中x=20,y=-25分之1
[(xy-2)(-xy-2)-4(xy-1)^2]除以(-xy)
=[-x²y²+4-4(x²y²-2xy+1)]÷(-xy)
=(-x²y²+4-4x²y²+8xy-4)÷(-xy)
=(-5x²y²+8xy)÷(-xy)
=5xy-8
=5×20×（-25分之1 ）-8
=-4-8
=-12

[(xy－2)(-xy－2)－4(xy－1)²]/(-xy)
＝[-(x²y²－4)－4(xy²－2xy＋1)]/(-xy)
＝(-5x²y²＋8xy－1)/(-xy)
＝5xy－8＋1/xy
x=20,y=-25分之1 xy＝20×(-1/25)＝-4/5
原式＝5×（-4/5）－8＋（-5/4）＝-4－8－5/4＝-53/4

=[(-2+xy)(-2-xy)-4(xy-1)^2]除以(-xy)
=[（-2）²-(xy)²-4(x²y²-2xy+1)]/(-xy)
=(4-x²y²-4x²y²+8xy-4)/(-xy)
=-(-5x²y²+8xy)/(xy)
=5xy-8

(-3xy+2xy)-(4xy+xy) 3xy-4xy-（-2xy） 1.3xy -4xy-(2xy) 3xy-4xy-（-2xy） (-4xy^3)×（-xy）+（-3xy^2）^2 （-3xy^2)^2+(-4xy^3)*(-xy)=多少 (-4xy^3)*(-xy)+(-3xy^2)^2 (3xy^2)^2+(-xy^3)(4xy) 计算-xy-(4z-2xy)-(3xy-4z) -xy(4z-2xy)-(3xy-4z) 化简 计算：3xy-4xy-（-2xy）要过程 （1）3xy-4xy-(-2xy) 3xy-4xy-(-2xy)的解法 3xy-4xy-(-2xy) 快啊,亲 3xy-3xy-xy+2yx 2xy.(-3xy)÷(xy) 2xy-xy-(-3xy)= xy^2-2xy+2y-4