1, <=>33+x=45
    <=>    x  = 12
Vậy x=12
2, <=>x+73 =102
    <=>   x    =29
3,x=2
4, -23+x=25<=>x=2
6, x-8=20<=>x=28

a) \(3\left(2-x\right)+5\left(x-6\right)=98\)

\(\Rightarrow6-3x+5x-30=98\)

\(\Rightarrow\left(6-30\right)+\left(-3x+5x\right)=98\)

\(\Rightarrow-24+2x=98\)

\(\Rightarrow2x=98-\left(-24\right)\)

\(\Rightarrow2x=122\)

\(\Rightarrow x=122:2\)

\(\Rightarrow x=61\)

Vậy x = 61

b) \(3x-2=2x-3\)

\(\Rightarrow3x-2x=2-3\)

\(\Rightarrow x=-1\)

Vậy x = -1

c) \(\left(x-7\right)\left(x^3-8\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x-7=0\\x^3-8=0\end{cases}}\Rightarrow\orbr{\begin{cases}x-7=0\\x^3=8\end{cases}}\Rightarrow\orbr{\begin{cases}x=7\\x=2\end{cases}}\)

Vậy x = 7 hoặc x = 2

_Chúc bạn học tốt_

a.6-3X+5X-30=98

2X-24=98

2X=74

X=37

b.3X-2X=2-3

X=-1

c.X-7=0 X=7

   X^3-8=0 X=2

2: \(=\dfrac{-2}{75}+\dfrac{5}{39}=\dfrac{33}{325}\)

3: \(=\dfrac{6}{11}\left(\dfrac{4}{9}+\dfrac{5}{9}\right)=\dfrac{6}{11}\)

4: \(=\dfrac{7}{19}\left(\dfrac{5}{13}+\dfrac{8}{13}-1\right)=-2\cdot\dfrac{7}{19}=-\dfrac{14}{19}\)

5: \(=\dfrac{2}{7}\left(\dfrac{4}{23}-\dfrac{27}{23}+1\right)=0\)

6: \(=\dfrac{3}{8}\left(\dfrac{3}{7}+\dfrac{4}{7}\right)+\dfrac{11}{8}=\dfrac{3}{8}+\dfrac{11}{8}=\dfrac{14}{8}=\dfrac{7}{4}\)

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

Trả lời

a)3/2 < x < 8/3

3/2=9/6        và          16/6

Các phân số lớn hơn 3/2 mà nhỏ hơn 8/3 là:

    10/6;11/6;12/6;13/6;...;15/6

Để thỏa mãn yêu cầu đề bài thì phân số đó phải viết được dưới dạng STN.

Vậy phân số phù hợp là: 12/6=2/1=2.

b) tương tự

49/25; 50/25; 51/25..55/25

Mà x là stn

=> x= 50/25=2

=>x=2

khó thế 

(1-2+3-4+.....-98+99)x(2013x6-2013-2013x5)

=(1-2+3-4+....-98+99)x[ 2013x(6-1-5)]

= (1-2+3-4+....-98+99)x(2013x0)

= (1-2+3-4+....-98+99)x0 = 0

=0

      \(\frac{7}{10}-\frac{3}{10}x\frac{1}{10}+\frac{4}{25}\)

\(=\frac{7}{10}-\frac{3}{100}+\frac{4}{25}\)

\(=\frac{70}{100}-\frac{3}{100}+\frac{4}{25}\)

\(=\frac{67}{100}+\frac{4}{25}\)

\(=\frac{67}{100}+\frac{16}{100}\)

\(=\frac{83}{100}=0,83\)

      \(\frac{6}{11}x\frac{3}{7}+\frac{3}{7}x\frac{5}{11}\)

\(=\frac{18}{77}+\frac{15}{77}\)

\(=\frac{33}{77}=\frac{3}{7}\)

     \(49x\left(311-4807:23\right)+98210\)

\(=49x\left(311-209\right)+98210\)

\(=49x102+98210\)

\(=4998+98210\)

\(=103208\)

a) \(\frac{7}{10}-\frac{3}{10}\times\frac{1}{10}+\frac{4}{25}\)

\(=\frac{2}{5}\times\frac{1}{10}+\frac{4}{25}\)

\(=\frac{1}{25}+\frac{4}{25}\)

\(=\frac{5}{25}=\frac{1}{5}\)

b)\(\frac{6}{11}\times\frac{3}{7}+\frac{3}{7}\times\frac{5}{11}\)

\(=\frac{3}{7}\times\left(\frac{6}{11}+\frac{5}{11}\right)\)

\(=\frac{3}{7}\times1\)

\(=\frac{3}{7}\)

c)\(49\times\left(311-4807:23\right)+98210\)

\(=49\times\left(311-209\right)+98210\)

\(=49\times102+98210\)

\(=4998+98210\)

\(=103208\)

7/10 - 3/10 x 1/10 + 4/25= 1/5

6/11 x 3/7 + 3/7 x 5/11 = 3/7

49 x ( 311 - 4807 : 23 ) + 98 210 = 10241

Bài 1:

$10+3(x-6)=5^{10}:5^8=5^2=25$

$3(x-6)=25-10=15$

$x-6=15:3=5$

$x=5+6=11$

Bài 2:

a. $100-[150-8(7-4)^2]=100-(150-8.3^2)=100-150+8.3^2$

$=-50+72=72-50=22$
b. $=-999-23+999-10-67=(-999+999)-10-(67+23)$

$=0-10-90=-(10+90)=-100$