a) \(3x-18.28:14=308\)

\(=>3x-36=308\)

\(=>3x=344\)\(\)

\(=>x=\frac{344}{3}\)

\(\)b)\(38+\left|x\right|=\left(-12\right)+65\)

\(=>38+\left|x\right|=53=>\left|x\right|=15=>\orbr{\begin{cases}x=15\\x=-15\end{cases}}\)

c)\(15+3.\left(x-1\right):5=30\)

\(=>15+3.\left(x-1\right)=150\)

\(=>3.\left(x-1\right)=135\)

\(x-1=45=>x=46\)

d) \(5.\left(7-3x\right)+7.\left(2+2x\right)=1\)

\(=>35-15x+14+14x=1\)

\(=>49-x=1=>x=48\)

e)\(3.\left(x-7\right)=21\)

\(=>x-7=7=>x=14\)

g)\(\left[\left(6x-72\right):2-84\right]:28=5628\)

\(\left(6x-72\right):2-84=157584\)

\(\left(6x-72\right):2=157668\)

\(6x-72=315336\)

\(6x=315408=>x=52568\)

h)\(123-5\left(x+4\right)=28\)

\(5.\left(x+4\right)=95\)

\(x+4=19=>x=15\)

p)\(14.\left(x-3\right)-138=73\)

\(14.\left(x-3\right)=211\)

\(x-3=\frac{211}{14}=>x=\frac{253}{14}\)

\(t\)

\(\left|x\right|-5=2\)

\(\left|x\right|=7=>\orbr{\begin{cases}x=7\\x=-7\end{cases}}\)

v)\(4x-72=\left|100-8.25\right|\)

\(4x-72=\left|-100\right|\)

\(4x-72=100=>4x=172=>x=43\)

cậu có thể tham khảo bài làm trên đây ạ, chúc cậu học tốt ^^

a) 7(x - 5) + 2 = 51

\(\Leftrightarrow\) 7(x - 5) = 51 - 2

\(\Leftrightarrow\) 7(x - 5) = 49

\(\Leftrightarrow\) x - 5 = 49 : 7

\(\Leftrightarrow\) x - 5 = 7

\(\Leftrightarrow\) x = 7 + 5

\(\Leftrightarrow\) x = 12.

Vậy x = 12.

k) 2412 : (3x + 147) = |-38| + (-26)

\(\Leftrightarrow\) 2412 : (3x + 147)= 38 + (-26)

\(\Leftrightarrow\) 2412 : (3x + 147)= 12

\(\Leftrightarrow\) 3x + 147 = 2412 : 12

\(\Leftrightarrow\) 3x + 147 = 201

\(\Leftrightarrow\) 3x = 201 - 147

\(\Leftrightarrow\) 3x = 54

\(\Leftrightarrow\) x = 54 : 3

\(\Leftrightarrow\) x = 18.

Vậy x = 18.

I) 4824 : (4x + 137) = |-59| + (-35)

\(\Leftrightarrow\) 4824 :(4x + 137) = 59 + (-35)

\(\Leftrightarrow\) 4824 :(4x + 137) = 24

\(\Leftrightarrow\) 4x + 137 = 4824 : 24

\(\Leftrightarrow\) 4x + 137 = 201

\(\Leftrightarrow\) 4x = 201 - 137

\(\Leftrightarrow\) 4x = 64

\(\Leftrightarrow\) x = 64 : 4

\(\Leftrightarrow\) x = 16.

Vậy x = 16.

c) |-123| - 5(x - 3) = (-28) + 66

\(\Leftrightarrow\) 123 - 5(x - 3) = 38

\(\Leftrightarrow\) 5(x - 3) = 123 - 38

\(\Leftrightarrow\) 5(x - 3) = 85

\(\Leftrightarrow\) x - 3 = 85 : 5

\(\Leftrightarrow\) x - 3 = 17

\(\Leftrightarrow\) x = 17 + 3

\(\Leftrightarrow\) x = 20.

Vậy x = 20.

m) 7x - 4 . 6 = 2058

\(\Leftrightarrow\) 7x - 24 = 2058

\(\Leftrightarrow\) 7x = 2058 + 24

\(\Leftrightarrow\) 7x = 2082

\(\Leftrightarrow\) x = 2082 : 7

\(\Leftrightarrow\) x = \(\frac{2058}{7}\).

Vậy x = \(\frac{2058}{7}\).

Phần b) ra phân số nên mình để mai làm và cả những bài còn lại nữa.

Chúc bạn học tốt !!!

---------------NHANH NHA MK ĐANG CẦN GẤP--------------

-----------------------------------------------------

Cau 1)

21+(x+23)=50

X+23=50-21

X=29-23

X=6

Cau 2)

125+(x-100)=150

X-100=150-125

X=25+100

X=125

a, 117 - \(x\) = 28 - (-7)

   117 - \(x\) = 28 + 7

    117 - \(x\) = 35

            \(x\) =  117 - 35

             \(x\) = 82

b, \(x\) - (-38 - 2\(x\)) = (-3) - 8 + 2\(x\) 

    \(x\) + 38 + 2\(x\) = - 11 + 2\(x\)

   3\(x\)  + 38       = - 11 + 2\(x\)

   3\(x\) - 2\(x\)        = - 11 - 38

   \(x\)                = - 49

 A )123 -5 ( x -4 ) = 38

=> x-4 = (123-38) :(-5)

=> x-4=-17

=> x= -17+4=-13

B ) ( 3x - 2⁴ ) 7³ = 2.7⁴

=> 3x-16= 2.7⁴ :7³=14

=> 3x=14+16=30

=> x=30:3=10

C ) ( 2600 + 6400 ) - 3x = 1200

=> 9000-3x=1200

=> 3x=9000-1200=7800

=> x=7800:3=2600

D ) [( 6x - 72 ) : 2 - 84 ] 28 = 5628

=> (6x-72) :2-84= 5628:28=201

=> 6x-72 = (201+84) .2=570

=> 6x=570 +72=642

=> x= 642:6=107

( L-IKE )

A) 123 - 5(x-4) = 38

   5(x-4) = 123 - 38

   x-4 = 85 : 5

   x = 17 + 4

   x= 21

B) (3x - 2⁴)7³ = 2.7⁴

    (3x - 2⁴) = 2.7⁴:7³

     3x = 14 + 2⁴

    x = 30 : 3 = 10

 C) (2600 + 6400) - 3x = 1200

      9000 - 3x = 1200

      3x = 9000 - 1200 

      x = 7800 : 3 = 2600

D) [(6x - 72) : 2 - 84].28 = 5628

     (6x - 72) : 2 - 84 = 5628 : 28 = 201

     (6x - 72) : 2 = 201 + 84 = 285

     6x - 72 = 285 . 2 = 570

     6x = 570 + 72 = 642

     x = 642 : 6 = 107   

Có thể thử lại đáp án

a) \(58+7x=100\)

\(=>7x=100-58\)

\(=>7x=42\)

\(=>x=42:7\)

\(=>x=6\)

b) \(3x-7=28\)

\(=>3x=28+7\)

\(=>3x=35\)

\(=>x=35:3\)

\(=>x=\dfrac{35}{3}\)

c) \(x-56:4=16\)

\(=>x-14=16\)

\(=>x=16+14\)

\(=>x=30\)

d) \(101+\left(36-4x\right)=105\)

\(=>36-4x=105-101\)

\(=>36-4x=4\)

\(=>4x=36-4\)

\(=>4x=32\)

\(=>x=32:4\)

\(=>x=8\)

e) \(\left(x-12\right):12=12\)

\(=>x-12=12.12\)

\(=>x-12=144\)

\(=>x=144-12\)

\(=>x=132\)

f) \(\left(3x-2^4\right).7^3=2.7^4\)

\(=>3x-2^4=2.7^4:7^3\)

\(=>3x-16=2.7=14\)

\(=>3x=14+16\)

\(=>3x=30\)

\(=>x=30:3\)

\(=>x=10\)

i) \(\left(10+2x\right).4^{2011}=4^{2013}\)

\(=>10+2x=4^{2013}:4^{2011}\)

\(=>10+2x=4^2=16\)

\(=>2x=16-10\)

\(=>2x=6\)

\(=>x=6:2\)

\(=>x=3\)

\(#WendyDang\)

A)

5.(x-4)=123-38

5.(x-4)=85

x-4=85:5

x-4=17

x=17+4

x=21

5.(x-4)=123-38

5.(x-4)=85

x-4=85:5

x-4=17

x=17+4

x=21

 Đúng 1000000000000000

1/ -7264 + (1543 + 7264)
=-7264 + 1543 + 7264=1543
2/ (144 – 97) – 144

=144-97-144=-97

3/ (-145) – (18 – 145)(Vì có dấu trừ ở trước ngoặc nên p đổi dấu)

=-145-18+145=-18

4/ 111 + (-11 + 27)

=111-11+27=137

1/ -7264 + (1543 + 7264)
=-7264 + 1543 + 7264=1543
2/ (144 – 97) – 144
=144-97-144=-97
3/ (-145) – (18 – 145)(Vì có dấu trừ ở trước ngoặc nên p đổi dấu)
=-145-18+145=-18
4/ 111 + (-11 + 27)
=111-11+27=137