Ta có:154+(50-7x)=22

50-7x=22-154

50-7x=-132

7x=50-(-132)

7x=182

x=182÷7

x=26

Vậy:x=26

ks nhé!Học tốt!;))

50-7x=154-22

50-7x=132

7x=50-132

x=-82

Ta có : 7x + 32 : 8 = 154 + 2x 

=> 7x + 4 = 154 + 2x

=> 7x - 2x = 154 - 4

=> 5x = 150

=> x = 30

7x - 2x = 154 - 4 <=> 5x = 150 => x = 30

\(\dfrac{1}{x^2+7x+10}+\dfrac{1}{x^2+13x+40}+\dfrac{1}{x^2+19x+88}+\dfrac{1}{x^2+25x+154}\)

\(=\dfrac{1}{\left(x+2\right)\left(x+5\right)}+\dfrac{1}{\left(x+5\right)\left(x+8\right)}+\dfrac{1}{\left(x+8\right)\left(x+11\right)}+\dfrac{1}{\left(x+11\right)\left(x+14\right)}\)

\(=\dfrac{1}{x+2}-\dfrac{1}{x+5}+\dfrac{1}{x+5}-\dfrac{1}{x+8}+\dfrac{1}{x+8}-\dfrac{1}{x+11}+\dfrac{1}{x+11}-\dfrac{1}{x+14}\)

\(=\dfrac{1}{x+2}-\dfrac{1}{x+14}\)

sai rồi !!! xem lại đi nhé =))

a) 

<=> 720 : [ 41 - ( 7x^2 - 5 ) ] = 40

<=>         41 - ( 7x^2 - 5 )      = 720 : 40

<=>         41 - ( 7x^2 - 5 )      = 18

<=>                  7x^2 - 5         = 41 - 18

<=>                  7x^2 - 5         = 23

<=>                 7x^2               = 23 + 5

<=>                 7x^2               = 28

<=>                  x^2                = 28 : 7

<=>                  x^2                = 4

<=>                  x^2                = 2^2

<=>                  x                   = 2

b) 10: 1/10

   40: 1/40

   88: 1/88

   154: 1/154

   238: 1/238

Rồi b tách mẫu số ra như sau:

\(\frac{1}{10}+\frac{1}{40}+\frac{1}{88}+\frac{1}{154}+\frac{1}{238}\)

=> \(\frac{1}{2\times5}+\frac{1}{5\times8}+\frac{1}{8\times11}+\frac{1}{11\times14}+\frac{1}{14\times17}\)

Đó rồi tính tiếp nha

a, 41-(7x^2-5)=720:40=18

7x^2-5=41-18=23

7x^2=23+5=28

x^2=28:7=4

x= 2 và -2

b, luôn bằng 0 có tính chất

\(\left(2x+1\right)^3+1^{40}=7\cdot2^2\)

\(\left(2x+1\right)^3=27\)

\(2x=2\)

\(x=1\)

\(\left(7x-2x\right)^2-1^3=2^3+3^3\)

\(\left(5x\right)^2=36\)

Th1:

\(5x=6\)

\(x=\frac{6}{5}\)

Th2:

\(5x=-6\)

\(x=-\frac{6}{5}\)

Vậy x= +- 6/5

\(\left(154-2x\right):x=12\)

\(14x=154\)

\(x=11\) 

5x84=420

12x35=420

7x22=154

11x14=154

2x77=154

5.x=420

x=420:5

x=84

12.x=420

x=420:12

x=35

7.x=154

x=154:7

x=22

11.x=154

x=154:11

x=14

2.x=154

x=154:2

x=77

\(154+46:154+68:154-97:154\)

\(\Leftrightarrow154+\left(46:154\right)+\left(68:154\right)-\left(97:154\right)\)

\(\Leftrightarrow154+\left(46+48-97\right):154\)

\(\Leftrightarrow154+17:154\)

\(\Leftrightarrow163\)