楚无云07
幼苗
共回答了15个问题采纳率:80% 举报
1.(b*4)*2
=(4b-20)*2
=[4(4b-20)-10]
=16-90
[(7*3)*4][(3*4)*8
=[(28-15)*4][(12-20)*8]
=(13*4 )(-8*8)
=(52-20)(-32-40)
=-2304
2.(2*5)*4
=[2+(2+1)+(2+2)+(2+3)+(2+5-1)]*4
=20*8
=20+(20+1)+(20+2)+..+(20+6)+(20+8-1)
=188
(3*4)*8
=[3+(3+1)+(3+2)+(3+4-1)]*8
=18*8
=[18+(18+1)+(18+2)+..+(18+6)+(18+8-1)]
=172
3.x*5=10
(x+5)/2=10
x=15
x*4=12
(x+4)/2=12
x=20
4.
1年前
10