12-2[2x2y-3x+4y]+3[x2y+4x-3y],其中x=1,y=-2.化简求值

急急急先把多项式化简,然后再把数带进去
2025-05-18 08:59:02
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回答1:

12-2[2x2y-3x+4y]+3[x2y+4x-3y]=12-4x2y+6x-8y+3x2y+12x-9y=12-x2y+18x-17y=12-12x(-2)+18x1+17x2=12+2+18+34=66