`@` `\text {Ans}`

`\downarrow`

`a,`

`(x-1954) \times 5=50`

`x-1954 = 50 \div 5`

`x-1954 = 10`

`x=10 + 1954`

`x= 1964`

`B.`

`48 - 40 \times x=8`

`40 \times x=48-8`

`40 \times x = 40`

` x=40 \div 40`

`x=1`

`C.`

`2+70 \div x = 3`

`70 \div x = 3-2`

`70 \div x = 1`

`x=70 \div 1`

`x=70`

`D. [3 \times (x+2) \div 7]  \times  4=120`

`3 \times (x+2) \div 7 = 120 \div 4`

`3 \times (x+2) \div 7 =30`

`3 \times (x+2) = 30 \times 7`

`3 \times (x+2)=210`

`x+2=210 \div 3`

`x+2=70`

`x=70-2`

`x=68`

`E.`

`7,2 \div [ (0,6 \times x+8) \div 20 + 59] = 0,12?` Thiếu ngoặc bạn nhé._.

\(a,\left(x-1954\right)\times5=50\\ x-1954=50:5\\ x-1954=10\\ x=1954+10\\ x=1964\\b.48-40\times x=8\\40\times x=48-8\\40\times x=40\\ x=40:40\\ x=1 \\ c.2+70:X=3\\ 70:x=3-2\\ 70:x=1\\ x=70:1\\ x=70\\ d,\left[3\times\left(x+2\right):7\right]\times4=120\\ 3\times\left(x+2\right):7-120:4\\ 3\times\left(x+2\right):7=30\\ \left(x+2\right):7=30:3\\ \left(x+2\right):7=10\\ x+2=10\times7\\ x+2=70\\ x=70-2\\ x=68\)

1a) x - 7 = -18

=> x = -18 + 7

=> x = -11

b) -2x + 8 = -24

=> -2x = -24 - 8

=> -2x = -32

=> x = -32 : (-2)

=> x = 16

c) 4 - 2x = 59

=> 2x = 4 - 59

=> 2x = -55

=> x = -55 : 2

=> x = -27,5

d) -36 - x = 59

=> x = -36 - 59

=> x = -95

k) -81 : x = (-3)

=> x = -81 : (-3)

=> x = 27

g) -16 : x = 2

=> x = -16 : 2

=> x = -8

m) (6 - 27) - (3 - x) = (-7) . (-8)

=> -21 - (3 - x) = 56

=> 3 - x = -21 - 56

=> 3 - x = -77

=>  x = 3 + 77

=> x = 80

a) x=-11

b) x=16

c) x= -27,5

d) x=95

a) 10-x-5=-5-7-11

=> 5 - x = -23

=> x = 28
b) |x| -3=0

=> |x| = 3

=> x = 3 hoặc x -3
c) ( 7-|x| ) .(2x-4)=0

=> 7 - |x| = 0 hoặc 2x - 4 = 0

=> |x| = 7 hoặc 2x = 4

=> x = 7 hoặc x = - 7 hoặc x = 2
c)2+3x=-15-19 

=> 2 + 3x = -34

=> 3x = 36

=> x = 12 
 

\(a,10-x-5=-5-7-11\)

\(10-x-5=-23\)

\(10-x=-18\)

\(x=28\)

\(b,|x|-3=0\)

\(|x|=3\)

\(\Rightarrow\orbr{\begin{cases}x=3\\x=-3\end{cases}}\)

=2x2/1x3 x 3x3/2x4x4/3x5 x ... x 11x11/10x12

=2x2x3x3x4x4x...x11x11/1x3x2x4x3x5x...x10x12

= 2x3x4x...x11)x(2x3x4x...x11)/(1x2x3x4x...x11)/(1x2x3x...x10)x(2x3x4x...x11)

=11x2/1x12

=22/12

=11/6

4/3x9/8x16/15x...x121/120=\(\dfrac{2^2}{1\cdot3}\)x\(\dfrac{3^2}{2\cdot4}\)x\(\dfrac{4^2}{3\cdot5}\)x...x\(\dfrac{11^2}{10\cdot12}\)=\(\dfrac{2}{3}\)x\(\dfrac{11}{10}\)=\(\dfrac{11}{15}\)

4/3x9/8x16/15x...x121/120=\(\dfrac{2^2}{1\cdot3}\)x\(\dfrac{3^2}{2\cdot4}\)x...x\(\dfrac{11^2}{10\cdot12}\)=\(\dfrac{2}{3}\)x\(\dfrac{11}{10}\)=\(\dfrac{11}{15}\)

\(8^{59}:16^{32}=2^{177}:2^{128}=2^{49}\)

a) \(47.69-31\left(-47\right)=47-69-\left(-31\right).47\)

\(=47.69+31.47=47.\left(69+31\right)=47.100=4700\)

b) \(16\left(38-2\right)-38\left(16-1\right)=16.38-16.2-38.16-\left(-38\right).1\)

\(=\left(16.38-38.16\right)-32+38=0-32+38=6\)

c) \(\left(-41\right)\left(59-2\right)+59\left(41-2\right)\) \(=\left(-41\right).59-\left[\left(-41\right).2\right]+59.41-59.2\)

\(=\left[\left(-41\right).59+59.41\right]-\left[\left(-49\right).2-51.2\right]=0-\left(-100\right).2=200\)

d) \(125.\left(-8\right)\left(-25\right)9.4.1000\div3=125.200.9.4.1000\div3\)

\(=\left(125.4\right)\left(9\div3\right)\left(200.1000\right)=500.3.200000=300000000\)

a) \(-524\cdot\left[23+\left(-45\right)\right]+524\cdot\left(-45+123\right)\)

\(=-524\cdot\left[\left(23-45\right)-\left(-45+123\right)\right]\)

\(=-524\cdot\left(23-45+45-123\right)\)

\(=-524\cdot-100\)

\(=52400\)

b) \(47\cdot69-31\cdot\left(-47\right)\)

\(=-47\cdot\left(-69-31\right)\)

\(=-47\cdot-100\)

\(=4700\)

c) \(16\left(38-2\right)-38\left(16-1\right)\)

\(=16\cdot38-16\cdot2-38\cdot16+38\)

\(=-16\cdot2+38\)

\(=-36+38\)

\(=2\)

d) \(\left(-41\right)\cdot\left(59+2\right)+59\cdot\left(41-2\right)\)

\(=-41\cdot59-41\cdot2+41\cdot59-2\cdot59\)

\(=-41\cdot2-2\cdot59\)

\(=-2\left(41+59\right)\)

\(=-2\cdot100\)

\(=-200\)

e) \(25\cdot\left(-8\right)\cdot\left(-25\right)\cdot9\cdot4\cdot100^0:3\)

\(=\left(-1000\right)\cdot\left(-25\right)\cdot9\cdot4\cdot1:3\)

\(=25000\cdot9\cdot4:3\)

\(=25000\cdot3\cdot4\)

\(=100000\cdot3\)

\(=300000\)

a: (x-35)-120=0

=>x-35=120

=>x=120+35=155

b: 59(x-29)=0

=>x-29=0

=>x=29

c: 2x+3x=45:3

=>5x=15

=>x=3

`@` `\text {Ans}`

`\downarrow`

`(x - 35) - 120 = 0`

`x - 35 = 0 + 120`

`x - 35 = 120`

`x = 120+ 35`

`x = 155`

Vậy, `x = 155`

____

`(x - 29)*59 = 0`

`x - 29 = 0 \div 59`

`x - 29 = 0`

`x = 0 + 29`

`x = 29`

Vậy, `x= 29`

____

`2x + 3x = 45 \div 3`

`(2 + 3)x = 15`

`5x = 15`

`x = 15 \div 5`

`x = 3`

Vậy, `x = 3.`