(5x-3y-2xy)-(6x+5y-2xy),其中x=-5,y=-1 【50-（7/9-11/12+1/6）*（-6）的二次方】除（-7）的二次方
问题描述：
(5x-3y-2xy)-(6x+5y-2xy),其中x=-5,y=-1 【50-（7/9-11/12+1/6）*（-6）的二次方】除（-7）的二次方
答
(5x-3y-2xy)-(6x+5y-2xy)=5x-3y-2xy-6x-5y+2xy=-x-8y 所以=-(-5)-8(-1)=5+8-13.
答
【1】(5x-3y-2xy)-(6x+5y-2xy)
=5x-3y-2xy-6x-5y+2xy
=-x-8y
将x=-5,y=-1代入，
-x-8y=-(-5)-8(-1)=5+8=13
【2】[50-（7/9-11/12+1/6）×（-6）²]÷(-7)²
=[50-(1/36×36)]÷49
=(50-1)÷49
=49÷49
=1 应该是这样吧
答
1、(5x-3y-2xy)-(6x+5y-2xy)
=5x-3y-2xy-6x-5y+2xy
=-x-8y
将x=-5,y=-1代入得 -（-5）-8（-1）=5+8=13
2、【50-（7/9-11/12+1/6）×（-6）^2】÷（-7）^2
=[50-(28/36-33/36+6/36)×36]÷49
=[50-1/36×36]÷49
=(50-1)÷49
=49÷49
=1
答
【1】(5x-3y-2xy)-(6x+5y-2xy)
=5x-3y-2xy-6x-5y+2xy
=-x-8y
将x=-5,y=-1代入，
-x-8y=-(-5)-8(-1)=5+8=13
【2】[50-（7/9-11/12+1/6）×（-6）²]÷(-7)²
=[50-(1/36×36)]÷49
=(50-1)÷49
=49÷49
=1