已知x+4y=-1.xy=5,求(6xy+7y)+((8x-(5xy-y+6x))
问题描述:
已知x+4y=-1.xy=5,求(6xy+7y)+((8x-(5xy-y+6x))
(())代表有中括号哦
答
原式=6xy+7y+8x-5xy+y-6x =xy+2(4y+x)=5-2=3
已知x+4y=-1.xy=5,求(6xy+7y)+((8x-(5xy-y+6x))
(())代表有中括号哦
原式=6xy+7y+8x-5xy+y-6x =xy+2(4y+x)=5-2=3