\(2x-\dfrac{1}{2}=-0,25\)

\(\Leftrightarrow2x-\dfrac{1}{2}=-\dfrac{1}{4}\)

\(\Leftrightarrow2x=\dfrac{1}{4}\)

\(\Leftrightarrow x=\dfrac{1}{8}\)

\(2x-\dfrac{-1}{2}=-0,25\)

\(2x-\dfrac{-1}{2}=-\dfrac{1}{4}\)

\(2x+\dfrac{1}{2}=-\dfrac{1}{4}\)

\(2x=\left(-\dfrac{1}{4}\right)-\dfrac{1}{2}\)

\(2x=-\dfrac{3}{4}\)

 \(x=-\dfrac{3}{4}:2\)

 \(x=-\dfrac{3}{8}\)

`2000+32,4:3xx0,25`

`=2000+8,1:3`

`=2000+2,7`

`=2002,7`

`34,8:x=7,2+2,8`

`34,8:x=10`

`x=34,8:10`

`x=3,48`

Vậy `x=3,48`

- Tính giá trị biểu thức:

2000 + 32,4 : 3 x 0,25

= 2000 : 10,8 x 0,25

= 2000 : 2,7

= 27

- Tìm x:

34,8 : x = 7,2 + 2,8

34,8 : x = 10

          x = 34.8 : 10

          x = 3.48

Chúc bạn học tốt!! ^^

1. 2000 + 32,4 : 3 x 0,25

= 2000 + 10,8 x 0,25

= 2000 + 2,7

=2002,7

2.  34,8 : x =7,2 +2,8

     34,8 : x =10

               x = 34,8 : 10

               x = 3,48

tick mình nhé !!1

a.

7,15 : 0,5 + 7,15 x 9 - 7,15

=7,15 x 2 + 7,15 x 9 - 7,15

=7,15 x (2 + 9 - 1)

=7,15 x 10

=71,5.

b.19,7 : 0,1 x 4 x 0,25
=(19,7 : 0,1) x (4x0,25)
=197 x 1
=197

[ 0,8 x 7 + (0,8)² ] x ( 1,25 x 7-4 x 1,25 ) + 31,64 = 55,04

hình như là 55,04

[0,8 x 7+(0,8)²]x(1,25x7-4x1,25)+31,64

=(5,6+0,64)x1,25x(7-4)+31,64

=6,24x1,25x3+31,64

=23,4+31,64

=55,04

a. 1,2−(x−0,8)=−2(0,9+x)1,2−(x−0,8)=−2(0,9+x)

⇔1,2−x+0,8=−1,8−2x⇔1,2−x+0,8=−1,8−2x

⇔−x+2x=−1,8−2⇔x=−3,8⇔−x+2x=−1,8−2⇔x=−3,8

Phương trình có nghiệm x = -3,8

b. 2,3x−2(0,7+2x)=3,6−1,7x2,3x−2(0,7+2x)=3,6−1,7x

⇔2,3x−1,4−4x=3,6−1,7x⇔2,3x−4x+1,7x=3,6+1,4⇔0x=5

a. 1.2-(x-0.8)=-2(0.9+x)1.2-(x-0.8)=-2(0.9+x)

<=>1.2-x+0.8=(-1.8-2x)1.2-x+0.8=-1.8-2x

<=>1.2-x+0.8+1.8+2x=-2.16-2.4x+0.8

<=>-x+2x+2.4x=-1.2-0.8-1.8-2.16+0.8

<=>3.4x=-5.16

<=>x=-5.16/3.4

<=>x=-258/17

\(x .\)\(\dfrac{1}{2}+\dfrac{3}{2}.x=\dfrac{4}{5}\) 

\(x.\)\((\dfrac{1}{2}+\dfrac{3}{2})=\dfrac{4}{5}\) 

\(x.2=\)\(\dfrac{4}{5}\)

\(x=\)\(\dfrac{4}{5}:2\)

\(x=\)\(\dfrac{4}{10}=\dfrac{2}{5}\)

vậy \(x =\)\(\dfrac{2}{5}\) 

\(x\times50\%+\dfrac{3}{2}\times x=0,8\)

\(\Leftrightarrow x\times\dfrac{50}{100}+\dfrac{3}{2}\times x=0,8\)

\(\Leftrightarrow x\times\dfrac{1}{2}+\dfrac{3}{2}\times x=\dfrac{4}{5}\)

\(\Leftrightarrow x\left(\dfrac{1}{2}+\dfrac{3}{2}\right)=\dfrac{4}{5}\)

\(\Leftrightarrow x\times2=\dfrac{4}{5}\)

\(\Leftrightarrow x=\dfrac{4}{5}:2\)

\(\Leftrightarrow x=\dfrac{4}{5}\times\dfrac{1}{2}\)

\(\Leftrightarrow x=\dfrac{2}{5}\)

\(=>x.\left(50\%+\dfrac{3}{2}\right)=0,8\)

\(=>x.\left(\dfrac{1}{2}+\dfrac{3}{2}\right)=\dfrac{4}{5}\)

\(=>2x=\dfrac{4}{5}\)

\(x=\dfrac{4}{5}\times\dfrac{1}{2}=\dfrac{4}{10}=\dfrac{2}{5}\)

\(\left|x-0,8\right|+\left(x^2-\dfrac{4}{5}x\right)^2=0\) 

Ta có:

\(\left|x-0,8\right|\ge0\forall x\) 

\(\left(x^2-\dfrac{4}{5}x\right)^2\ge0\forall x\) 

\(\Leftrightarrow\left|x-0,8\right|=0\) hoặc \(\left(x^2-\dfrac{4}{5}x\right)^2=0\) 

\(\Rightarrow x-0,8=0\) hoặc \(x^2-\dfrac{4}{5}x=0\) 

         \(x=0,8\) hoặc \(x=0\) hoặc \(x=\dfrac{4}{5}\) 

Vậy \(x\in\left\{0;0,8;\dfrac{4}{5}\right\}\)

kết quả 576 nha bạn 

          click cho mk nha

0,8*90+1,6*2+0,8*6

=0,8*90+0,8*2*2+0,8*6

=0,8*(90+2+2+6)

=0,8*100

=80

0,8x90+1,6x2+0,8x6=0,8x(90+6)+1,6x2=0,8x96+1,6x2=76,8+3,2=80

k cho mình nha !!!

Bằng 1 UwU

cần phải nói hết bước làm ra ạ

   0,8 x 0,5 x 1,25 x 2,5 x 2 x 0,4

= (0,8 x 1,25) x (0,5 x 2) x (2,5 x 0,4)

= 1 x 1 x 1

= 1