Không khó đâu nhé em:

\(75\%+\frac{1}{4}-\frac{1}{4}:0,25+\frac{1}{8}:0,125-\frac{1}{2}:0,5\)  

\(=\frac{3}{4}+\frac{1}{4}-\frac{1}{4}:\frac{1}{4}+\frac{1}{8}:\frac{1}{8}-\frac{1}{2}:\frac{1}{2}\)

\(=\frac{3}{4}+\frac{1}{4}-1+1-1\)

\(=1-1+1-1\)

\(=0\)

Kết quả là 1,75

\(\frac{1}{2}:0,5-\frac{1}{4}:0,25+\frac{1}{8}:0,125+75\%\)

\(=\frac{1}{2}\cdot2-\frac{1}{4}\cdot4+\frac{1}{8}\cdot8+0,75\)

\(=1+1+1+0,75\)

\(=3,75\)

Nhầm :

\(=1-1+1+0,75\)

\(=1,75\)

1/2×(2×x-3)+105/2=-137/2

1/2×(2×x-3)=-137/2-105/2

1/2×(2×x-3)=-242/2

2×x-3=-242/2:1/2

2×x-3=-242

2.x=(-242)+3

2.x=239

x=239:2

x=239/2

A,-12×25-25×75-25×13

=[(-12)-75-13].25

=(-100).25

-2500

B,-50/7×49/10-35/2×-10/7+ -25/3× -9/5

=(-35)-(-25)+(-13)

=-23

C,-354+265-156+125

=[(-354)-156]+(265+125)

=(-510)+277

=-233

D,-74+40-50+16-35

=(-74)+40+(-50)+16+(-35)

=[(-74)+(-35)]+[40+(-50)+16]

=(-109)+26

=-83

E,-2/3×4/5+-4/5×4/3-0,125

=-2/3.4/5+4/5.(-4/3)-0,125

=4/5.[-2/3+(-4/3)]-0,125

=4/5.(-2)-0,125

=-8/5-0,125

=(-1,6)+(-0,125)

=-1,725

Câu 1.0,5+0,5=1

Câu 2.0,25+0,25=0,5

Câu 3.0,125+0,125=0,25

Câu 4.0,0625+0,0625=0,125

Câu 5.15,39+25,5=40,89

1.=1

2.=0,5

3.=0,25

4.=0,125

5.=4089.

câu 1 ; 1

câu 2: 0,5

câu 3;0.25

câu 4 : 0.125

câu 5 :40,89

\(\dfrac{1}{2}:0,5+\dfrac{1}{4}:0,25+\dfrac{1}{8}:0,125\)

\(=\dfrac{1}{2}\times2+\dfrac{1}{4}\times4+\dfrac{1}{8}\times8\)

\(=\dfrac{2}{2}+\dfrac{4}{4}+\dfrac{8}{8}=1+1+1=3\)

1/2 : 0,5 + 1/4 : 0,25 + 1/8 :0,25

đổi 1/2=0,5;1/4=0,25;1/8=0,125

=0,5:0,5+0,25:0,25+0,125:0,125

=1+1+1

=3

\(=\dfrac{1}{4}:\dfrac{1}{4}-\dfrac{1}{8}:\dfrac{1}{8}+\dfrac{1}{2}:\dfrac{1}{2}-\dfrac{1}{10}\)

\(=1-1+1-\dfrac{1}{10}\)

= 0,9

\(\dfrac{1}{4}:0,25-\dfrac{1}{8}:0,125+\dfrac{1}{2}:0,5-\dfrac{1}{10}\\ =\dfrac{1}{4}:\dfrac{1}{4}-\dfrac{1}{8}:\dfrac{1}{8}+\dfrac{1}{2}:\dfrac{1}{2}-\dfrac{1}{10}\\ =1-1+1-\dfrac{1}{10}\\ =\left(1-1\right)+\left(1-\dfrac{1}{10}\right)\\ =1-\dfrac{1}{10}\\ =\dfrac{10-1}{10}=\dfrac{9}{10}\)

=1/4:1/4-1/8:1/8+1/2:1/2-1/10

=1-1+1-1/10

=1-1/10

=9/10

`1/4:0,25-1/8:0,125+1/2:0,5-1/10`

`=1/4 : 1/4 - 1/8 : 1/8 + 1/2 :1/2 - 1/10 `

`=1/4 . 4/1 - 1/8 . 8/1 + 1/2 . 2/1 - 1/10`

` = 1  - 1 + 1 - 1/10 `

`=  1 - 1/10 `

`= 10/10 - 1/10 `

`=9/10`