a. 2^x.4=128

    2^x   =32

=> x = 5

b. 2x+1=125

    2x    = 125-1

    2x    = 124

      x    = 62

c. x¹⁵=x

    => x \(\in\left\{0;\pm1\right\}\)

a) \(38,7\times\left(38,7-x\right)=38,7\)

\(38,7-x=38,7:38,7\)

\(38,7-x=1\)

\(x=38,7-1\)

\(x=37,7\)

De phan b) co bi nham khong ban ^.^

a ,x = 70

b, x = 50

c , x +e uxwrty (908 , 079

0,1 + 0,2 +...+ 0,x = 4,5

=> 10 x (0,1 + 0,2 +...+ 0,x) = 4,5 x 10

=> 1 + 2 +...+ x = 45

=> (x + 1)x : 2 = 45

=> (x + 1)x = 90

=> (x + 1)x = 10.9

=> x = 9

câu hỏi của mình cần giải rõ nha . giai nhanh giup mình

a ) ( x + 74 ) - 318 = 200

x + 74 = 200 + 318

x + 74 = 518

x = 518 - 74

x = 444

b ) 3636 : ( 12 . x - 91 ) = 36

12 . x - 91 = 3636 : 36

12 . x - 91 = 101

12 . x = 101 + 91

12 . x = 192

x = 192 : 12

x = 16

c ) ( x : 23 + 45 ) . 67 = 8911

x : 23 + 45 = 8911 : 67

x : 23 + 45 = 133

x : 23 = 133 - 45

x : 23 = 88

x = 88 . 23

x = 2024

d ) ( 3 . x - 6 ) + 57 = 60

3 . x - 6 = 60 - 57

3 . x - 6 = 3

3 . x = 3 + 6

3 . x = 9

x = 9 : 3

x = 3

\(a)\) \(\left(x+74\right)-318=200\)

\(x+74=518\)

\(x=444\)

Vậy x = 444

\(b)\) \(3636:\left(12x-91\right)=36\)

\(12x-91=101\)

\(12x=192\)

\(x=16\)

Vậy x = 16

\(c)\) \(\left(x:23+45\right)67=8911\)

\(x:23+45=133\)

\(x:23=88\)

\(x=2024\)

Vậy x = 2024

\(d)\left(3x-6\right)+57=60\)

\(3x-6=3\)

\(3x=9\)

\(x=3\)

Vậy x = 3

a. 420 : (x : 39) = 105

x : 39 = 420 : 105

x : 39 = 4

x = 4 x 39

x = 156

b. 200 - 18 : (372 : 3 : x - 1) - 28 = 166

200 - 28 - 166 = 18 : (372 : 3 : x - 1)

6 = 18 : (124 : x - 1)

18 : (124 : x - 1) = 6

124 : x - 1 = 18 : 6

124 : x - 1 = 3

124 : x = 4

x = 124 : 4

x = 31

c. 429 : (x + 31) = 11

x + 31 = 429 : 11

x + 31 = 39

x = 39 - 31

x = 8

d. 1615 : (X x 19) = 17

X x 19 = 1615 : 17

X x 19 = 95

X = 95 : 19

X = 5

cho mình xin tick nhé !

a: 420:(x:39)=105

=>\(x:39=420:105=4\)

=>\(x=4\times39=156\)

b: \(200-18:\left(372:3:x-1\right)-28=166\)

=>\(172-18:\left(124:x-1\right)=166\)

=>\(18:\left(124:x-1\right)=172-166=6\)

=>\(124:x-1=18:6=3\)

=>\(124:x=3+1=4\)

=>\(x=\frac{124}{4}=31\)

c: \(429:\left(x+31\right)=11\)

=>x+31=429:11=39

=>x=39-31=8

d: \(1615:\left(x\times19\right)=17\)

=>\(x\times19=1615:17=95\)

=>x=95:19=5