a与b互为相反数,c与d互为倒数,x=4(a+2)-(a-3b),y=c²d+d²-(d/c+c-1),求xy/4-(3x-5y)/8的值.y=c²d+d²-(d/c+c-1),=c+d²-(d/c+c-1)通分=(c^2+cd^2-d-c^2+c)/c=1

来源:学生作业帮助网 编辑:六六作业网 时间:2024/12/21 03:31:52
a与b互为相反数,c与d互为倒数,x=4(a+2)-(a-3b),y=c²d+d²-(d/c+c-1),求xy/4-(3x-5y)/8的值.y=c²d+d²-(

a与b互为相反数,c与d互为倒数,x=4(a+2)-(a-3b),y=c²d+d²-(d/c+c-1),求xy/4-(3x-5y)/8的值.y=c²d+d²-(d/c+c-1),=c+d²-(d/c+c-1)通分=(c^2+cd^2-d-c^2+c)/c=1
a与b互为相反数,c与d互为倒数,x=4(a+2)-(a-3b),y=c²d+d²-(d/c+c-1),求xy/4-(3x-5y)/8的值.
y=c²d+d²-(d/c+c-1),
=c+d²-(d/c+c-1)通分
=(c^2+cd^2-d-c^2+c)/c
=1

a与b互为相反数,c与d互为倒数,x=4(a+2)-(a-3b),y=c²d+d²-(d/c+c-1),求xy/4-(3x-5y)/8的值.y=c²d+d²-(d/c+c-1),=c+d²-(d/c+c-1)通分=(c^2+cd^2-d-c^2+c)/c=1
a与b互为相反数
所以:a+b=0
c与d互为倒数
所以:cd=1
x=4(a+2)-(a-3b),
=3(a+b)+8
=8
y=c²d+d²-(d/c+c-1),
=c+d²-(d/c+c-1)通分
=(c^2+cd^2-d-c^2+c)/c
=1
将x=8,y=1带入xy/4-(3x-5y)/8式子中
得出:-3/8