2-15/16÷5/7÷3/4 9/20÷[1/2×(2/5+4/5)] X-5/8X=1

2-15/16÷5/7÷3/4
=2-15/16*7/5*4/3
=2-7/4
=1/4

9/20÷[1/2×(2/5+4/5)]
=9/20/[1/2*6/5]
=9/20*5/3
=3/4

X-5/8X=1/3×45
3x/5=15
x=25

1/2X-1/3X+3/5X+2/5=5
(1/2-1/3+3/5)x=4.6
23x/30=4.6
x=6.9

0.8：4=X：8
4x=6.4
x=1.6本回答被提问者采纳

2-15/16÷5/7÷3/4
=2- 21/ 16 ÷3/4
=2- 7/4
=1/4 =0.25

9/20÷[1/2×(2/5+4/5)]
=9/20/[1/2×6/5]
=9/20×5/3
=3/4
X-5/8X=1/3×45
X-5/8X=15
3/8X=15
X=15÷8/3
X= 40

1/2X-1/3X+3/5X+2/5=5
1/6X +3/5X+2/5=5
23/30X+2/5=5
23/30X=5-2/5
23/30X=23/5
X=23/5 ÷23/30
X=6

0.8：4=X：8
0.8 ÷4=X ÷8
0.2=X ÷8
X=0.2×8
X=1.6

1、2-15/16÷5/7÷3/4

=2-15/16*7/5*4/3
=2-7/4
=8/4-7/4
=1/4

2、9/20÷[1/2×(2/5+4/5)]

=9/20/[1/2*6/5]
=9/20/3/5
=9/20*5/3
=3/4

3、X-5/8X=1/3×45

3/8X=15
X=15*8/3
X=40

4、1/2X-1/3X+3/5X+2/5=5

(1/2-1/3+3/5)X=5-2/5
23/30X=23/5
X=6

5、0.8：4=X：8
4X=6.4
X=1.6