a, \(\left(x-158\right):6=20\)

\(x-158=20.6\)

\(x-158=120\)

\(x=120+158\)

\(x=278\)

~~~Hok tốt~~~

a) \(\left(x-158\right):6=20\)

\(\Leftrightarrow x-158=\frac{20}{6}=\frac{10}{3}\)

\(\Leftrightarrow x=\frac{10}{3}+158\)

\(\Leftrightarrow x=\frac{484}{3}\)

Vậy : \(x=\frac{484}{3}\)

b) \(x-1,25.4=2,5\)

\(\Leftrightarrow x-5=2,5\)

\(\Leftrightarrow x=2,5+5\)

\(\Leftrightarrow x=7,5\)

Vậy : \(x=7,5\)

c) \(x+0,25=\frac{43}{4}-\frac{18}{5}\)

\(\Leftrightarrow x+\frac{1}{4}=\frac{143}{20}\)

\(\Leftrightarrow x=\frac{143}{20}-\frac{1}{4}\)

\(\Leftrightarrow x=\frac{69}{10}\)

Vậy : \(x=\frac{69}{10}\)

b, \(x-1,25.4=2.5\)

\(x-5=2,5\)

\(x=2,5+5\)

\(x=7.5\)

~~~Hok tốt ~~~

a.

\(1,25\times4-x=2,5\)

\(5-x=2,5\)

\(x=5-2,5\)

\(x=2,5\)

b.

\(\left(158-x\right)\div7=20\)

\(158-x=20\times7\)

\(158-x=140\)

\(x=158-140\)

\(x=18\)

c.

\(x-0,25=\frac{43}{4}-\frac{18}{5}\)

\(x-\frac{1}{4}=\frac{43}{4}-\frac{18}{5}\)

\(x=\frac{43}{4}-\frac{18}{5}+\frac{1}{4}\)

\(x=\left(\frac{43}{4}+\frac{1}{4}\right)-\frac{18}{5}\)

\(x=\frac{44}{4}-\frac{18}{5}\)

\(x=11-\frac{18}{5}\)

\(x=\frac{37}{5}\)

a. 1,25 × 4 - x = 2,5

5- x= 2,5

x= 5-2,5

x=2,5

b.(158- x) :7= 20

158- x= 20x7

158 -x= 140

x=158- 140

x=18

c. x- 0,25= \(\frac{43}{4}+\frac{18}{5}\)

x- 0,25=14,35

x= 14,35+ 0,25

x=14,6

a. 1,25 × 4 - x = 2,5

5- x= 2,5

x= 5-2,5

x=2,5

b.(158- x) :7= 20

158- x= 20x7

158 -x= 140

x=158- 140

x=18

Trả lời :

a) \(1,25\times4-x=2,5\)

\(5-x=2,5\)

\(x=5-2,5\)

\(x=2,5\)

~HT~

x - 0,25 = 43/4 + 18/5

\(x-\frac{1}{4}=\frac{287}{20}\)

\(x=\frac{287}{20}+\frac{1}{4}\)

\(x=\frac{73}{5}\)

\(x-0,25=\frac{43}{4}+\frac{18}{5}\)

\(\Rightarrow x-\frac{1}{4}=\frac{43}{4}+\frac{18}{5}\)

\(\Rightarrow x-\frac{1}{4}=\frac{287}{20}\)

\(\Rightarrow x=\frac{287}{20}+\frac{1}{4}\)

\(\Rightarrow x=\frac{73}{5}\)

\(\Rightarrow x=14,6\)

\(x-0,25=\frac{43}{4}+\frac{18}{5}\)

\(x-\frac{1}{4}=\frac{287}{20}\)

\(x=\frac{287}{20}+\frac{1}{4}\)

\(x=\frac{73}{5}\)

1. \(x-8+32=68\)

\(x-8=68-32\)

\(x-8=36\)

\(x=36+8\)

\(x=44\)

_____

2. \(x+8+32=68\)

\(x+8=68-32\)

\(x+8=36\)

\(x=36-8\)

\(x=28\)

_____

3. \(98-x+34=43\)

\(98-x=43-34\)

\(98-x=9\)

\(x=98-9\)

\(x=89\)

_____

4. \(98+x-34=43\)

\(98+x=43+34\)

\(98+x=77\)

\(x=77-98\)

\(x=-21\)

_____

5. \(x:5:4=800\)

\(x:5=800.4\)

\(x:5=3200\)

\(x=3200.5\)

\(x=16000\)

_____

6. \(18+x=384:8\)

\(18+x=48\)

\(x=48-18\)

\(x=30\)

_____

7. \(\left(84,6-2\times x\right):3,02=5,1\)

\(84,6-2.x=5,1.3,02\)

\(84,6-2.x=15,402\)

\(2.x=84,6-15,402\)

\(2.x=69,198\)

\(x=69,198:2\)

\(x=34,599\)

_____

8. \(x\times5=120:6\)

\(x.5=20\)

\(x=20:5\)

\(x=4\)

_____

9. \(\left(15\times24-x\right):0,25=100:0,25\)

\(\left(15.24-x\right):0,25=400\)

\(15.24-x=400.0,25\)

\(15.24-x=100\)

\(360-x=100\)

\(x=360-100\)

\(x=260\)

1,x-8+32=68

=>x-8=68-32=36

=>x=36+8=42

2,x+8+32=68

=>x+8=68-32=36

=>x=36-8=28

3,98-x+34=43

=>98-x=43-34=9

=>x=98-9=89

4,98+x-34=43

=>98+x=43+34=77

=>x=77-98=-21

5,x:5:4=800

=>x:20=800

=>x=800x20=16000

6,18+x=384:8=48

=>x=48-18=30

7,(84,6-2x):3,02=5,1

=>84,6-2x=5,1x3,02=15,402

=>2x=84,6-15,402=69,198

=>x=69,198:2=34,599

8,5x=120:6=20

=>x=20:5=4

9,(15x24-x):0,25=100:0,25=400

=>360-x=400x0,25=100

=>x=360-100=260.

1. \(...\Rightarrow x+24=68\Rightarrow x=68-24=44\)

2. \(...\Rightarrow x+40=68\Rightarrow x=68-40=28\)

3. \(...\Rightarrow3^{2\left(8+x\right)}=9=3^2\Rightarrow2\left(8+x\right)=2\Rightarrow8+x=1\Rightarrow x=-7\)

4. \(...\Rightarrow3^{2\left(8+x\right)}=77\) (bạn xem lại đề)

5. \(...\Rightarrow x:5=800.4\Rightarrow x:5=3200\Rightarrow x=3200.5=16000\)

6. \(...\Rightarrow18+x=48\Rightarrow x=48-18=30\)

7. \(...\Rightarrow84,6-2x=5,1.3,02=15,402\Rightarrow2x=84,6-15,402\Rightarrow2x=69,198\Rightarrow x=34,599\)

8. \(...\Rightarrow5.x=20\Rightarrow x=20:5=4\)

9. \(\left(360-x\right):0,25=400\Rightarrow360-x=400.0,25=100\Rightarrow x=400-100=300\)

a) Ta có: \(2\sqrt{9x-27}-\dfrac{1}{5}\sqrt{25x-75}-\dfrac{1}{7}\sqrt{49x-147}=20\)

\(\Leftrightarrow6\sqrt{x-3}-\sqrt{x-3}-\sqrt{x-3}=20\)

\(\Leftrightarrow4\sqrt{x-3}=20\)

\(\Leftrightarrow x-3=25\)

hay x=28

b) Ta có: \(\sqrt{9x+18}-5\sqrt{x+2}+\dfrac{4}{5}\sqrt{25x+50}=6\)

\(\Leftrightarrow3\sqrt{x+2}-5\sqrt{x+2}+4\sqrt{x+2}=6\)

\(\Leftrightarrow2\sqrt{x+2}=6\)

\(\Leftrightarrow x+2=9\)

hay x=7

8,75 x X + 0,75 + 1,25 x X + 0,25 = 20 + 0,25 + 0,75

8,75 x X + 0,75 + 1,25 x X + 0,25 = 20 + 1

8,75 x X + 0,75 + 1,25 x X + 0,25 = 21

( 8,75 + 1,25 ) x X + ( 0,75 + 0,25) = 21

10 x X + 1 = 21

10 x X       = 21 - 1

10 x X       = 20

       X       =  20 : 10

       X       = 2

tk nha

8,75x X+0,75+1,25x X +0,25=20+1/4+0,75

8,75x X +0,75+1,25x X +0,25=21

(8,75+0,25)xX+0,75=21

9xX+0,75=21

9xX=21-0,75

9xX=20,25

X=20,25:9

X=2,25

mk nhanh nhất tk nha

8,75 x X + 0.75 +1,25 x X + 0,25 = 20 + 1/4 + 0,75

=> 8,75x + 0,75 + 1,25x + 0,25 = 20 + 1/4 + 0,75

=> 8,75x + 1,25x = 20 

=> 10x = 20

=> x = 2

Vậy x là 2

x+0,25=3,6+10,75

x+0,25=14,35

x+0,25=14,35-0,25

x+0,25=14,1

x        =14,1-0,25

x=13,85

ta có
x + 0,25 = 43/4 - 18/5
=> x + 1/4 = 143/20
=> x = 143/20 - 1/4
=> x = 25/4
vậy x = 25/4

`x+0,25=18/5+43/4`

`x+0,25=3,6+10,75`

`x=3,6+10,5`

`x=14,1`

Vậy `x=14,1`

   `x+0,25=18/5+43/4`

`⇔x+1/4=18/5+43/4`

`⇔ x-18/5=43/4-1/4`

`⇔ x-18/5=42/4=21/2`

`⇔ x-36/10=105/10`

`⇔ x=141/10`