Question

m-{n-2m+[3m+(6m+3n)+5n]} 先化简再求值,其中m=二分之一 n=1？

Answer 1

m-{n-2m+[3m+(6m+3n)+5n]}
=m-{n-2m+[3m+6m+3n+5n]}
=m-{n-2m+[9m+8n]}
=m-{n-2m+9m+8n}
=m-{7m+9n}
=m-7m-9n
=-6m-9n
=-6*1/2-9*1
=-3-9
=-12,2,m-{n-2m+[3m+(6m+3n)+5n]}
=m-[n-2m+(3m+6m+3n+5n)]
=m-(n-2m+9m+8n)
=m-7m-9n
=-6m-9n
=-3-9
=-12,2,m-{n-2m+[3m+(6m+3n)+5n]}
=m-n+2m-[3m+(6m+3n)+5n]
=3m-n-3m-(6m+3n)-5n
=-6n-(6m+3n)
=-6n-6m-3n
=-9n-6m
=-9×1-6×1/2
=-9-3
=-12,2,把哪些小括号大括号中括号全部去掉，直接加减，再代值就行了。,2,m-{n-2m}+[9m+8n]=10m+7n
代人m、n的值得
5+7=12,1,化简原式=m-n-2m+3m+6m+3n+5n=8m+7n
代入数值=11,1,先化简
原式=m-{n-2m+[9m+8n]}
=m-{7m+9n}
=-6m-9n
把m=1/2和n=1代入得
原式=-12
上面的说的什么啊,1,m-{n-2m+[3m+(6m+3n)+5n]}
=m-n+2m-(3m+6m+3n+5n)
=3m-n-(9m+8n)
=3m-n-9m-8n
=-6m-9n
=-6*1/2-9*1
=-3-9
=-12,1,化简原式=-9n-6m=-12,1,原式=m-{n-2m+[9m+8n]}
=8m-9n
其中m=二分之一 n=1 时，=8m-9n=8*0.5-9=-5,0,m-{n-2m+[3m+(6m+3n)+5n]}
=m-[n-2m+(3m+6m+3n+5n)]
=m-(n-2m+9m+8n)
=m-7m-9n
=-6m-9n
=-3-9
=12
希望能帮上你。,0,