已知X+Y=6,XY=-4,求(5X-4Y-3XY)-(8X-Y+2XY)的值

来源:学生作业帮助网 编辑:作业帮 时间:2024/10/03 15:25:49
已知X+Y=6,XY=-4,求(5X-4Y-3XY)-(8X-Y+2XY)的值
x){}K##mt""muMtmlz4B$R8"N] "B7R}>i"} tPj;~`%Ƒ ̴MLml ΰsk 2 v==`g Ov/%$[]C m#و

已知X+Y=6,XY=-4,求(5X-4Y-3XY)-(8X-Y+2XY)的值
已知X+Y=6,XY=-4,求(5X-4Y-3XY)-(8X-Y+2XY)的值

已知X+Y=6,XY=-4,求(5X-4Y-3XY)-(8X-Y+2XY)的值
(5X-4Y-3XY)-(8X-Y+2XY)
=-(3X+3Y)-5XY=-3*6+4*5=2

(5X-4Y-3XY)-(8X-Y+2XY)=-3X-3Y-5XY
因为X+Y=6,XY=-4,所以(5X-4Y-3XY)-(8X-Y+2XY)=-3X-3Y-5XY=-18+20=2