x x 7 = 357 => x = 357 : 7 = 51

xx +x+52=100

xx + x = 52 - 100

xx +x = 48

x *11 + x = 48

x *(11+1)=48

x * 12 = 48 

        x = 48 : 12 

           x= 4

3 x = 100 - 52 = 48

x = 48 : 3 = 16

Đáp số: x = 16

90 : xx = 6    

=> xx = 90 : 6 = 15

x + xx + 5 = 125

x + xx = 125 - 5

x + xx = 120

x + x * 11 = 120

x * ( 11 + 1 ) = 120

x * 12 = 120

x = 120 : 12

x= 10

Vậy x = 10

x + xx + 5 = 125

x + xx = 125 - 5

x + xx = 120

x + X x 2 = 120

X x 3 = 120

      X = 120 : 3

      X = 40

a)

`6xx(x+9845)=29042xx6`

`6xx(x+9845)=174252`

`x+9845=174252:6`

`x+9845=29042`

`x=29042-9845`

`x=19197`

b)

`(x:3)xx8=8xx3`

`(x:3)xx8=24`

`x:3=24:8`

`x:3=3`

`x=3xx3`

`x=9

Lời giải:

a. 

$6\times (x+9845)=29042\times 6$

$x+9845=29042\times 6:6=29042$

$x=29042-9845=19197$

b.

$(x:3)\times 8=8\times 3$

$(x:3)=8\times 3:8=3$

$x=3\times 3=9$

x=29 ( Vì 29x8=232, lớn nhất)

x=228

X x 3=6/5+3

=>X x 3=6/5+3/1=6/5+15/5=21/5

=>X x 3=21/5

=>X=21/5 : 3=21/5 x 1/3=7/5

 Vậy, x = 7/5

$\text{x × 3 = $\dfrac{6}{5}$ + 3}$

$\text{x × 3 = $\dfrac{21}{5}$}$

$\text{x = $\dfrac{21}{5}$ ÷ 3}$

$\text{x = $\dfrac{7}{5}$}$

$\text{Vậy x = $\dfrac{7}{5}$}$

x x 6 = 7872     3 x x = 1395

x = 7872 : 6     x = 1395 : 3

x = 1312     x = 465.