帮我解一道应用题和几道计算题!应用题是“一条红领巾的底长是十分之九米,高是三分之一米.做500条这样的红领巾至少要用红布
1个回答

S=500*1/2(9/10*1/3)=75m2

1.3/4*8/9=2/3,(3,9约,4,8约),前面是要1-吗?那答案是1/3

2.(3/4-1/2)*16

=(3/4-2/4)*16

=1/4*16

=4

3.9-(1-1/5)*3/4

=9-(5/5-1/5)*3/4

=9- 4/5*3/4

=9-3/5

=45/5-3/5

=42/5

=8又2/5

4.7又八分之一+1又九分之二+1又八分之一+8又九分之七

=57/8+11/9+9/8+77/9

=(57/8+9/8)+(11/9+77/9)

=66/8+88/9

=18又1/36