Question

tìm x:

a,32:(3xX-2)=8

b,75:(X-18)=25

c,(15-6xX)x243=729

d,4x(X-12)+9=17

e,20-2x(X+4)=4

 

Answer 1

a) 32 : (3.x - 2) = 8

3x - 2 = 32 : 8

3x - 2 = 4

3x = 4 + 2

3x = 6

x = 6 : 3

x = 2

b) 75 : (x - 18) = 25

x - 18 = 75 : 25

x - 18 = 3

x = 3 + 18

x = 21

c) (15 - 6.x) . 243 = 729

15 - 6x = 729 : 243

15 - 6x = 3

6x = 15 - 3

6x = 12

x = 12 : 6

x = 2

d) 4.(x - 12) + 9 = 17

4(x - 12) = 17 - 9

4(x - 12) = 8

x - 12 = 8 : 4

x - 12 = 2

x = 2 + 12

x = 14

e) 20 - 2.(x + 4) = 4

2(x + 4) = 20 - 4

2(x + 4) = 16

x + 4 = 16 : 2

x + 4 = 8

x = 8 : 2

x = 4

Answer 2

`32: ( 3xx x -2)=8`

`3xx x-2=32:8`

`3xx x-2=4`

`3 xx x=4+2`

`3xx x=6`

`x=6:3`

`x=2`

__

`75 : (x-18) =25`

`x-18=75:25`

`x-18= 3`

`x=3+18`

`x=21`

__

`(15-6 xx x ) xx 243 =729`

`15-6 xx x = 729 : 243`

`15-6 xx x = 3`

`6 xx x=15-3`

`6 xx x=12`

`x=12:6`

`x=2`

__

`4 xx (x-12)+9=17`

`4 xx (x-12)=17-9`

`4 xx (x-12)= 8`

`x-12=8:4`

`x-12=2`

`x=2+12`

`x=14`

__

`20-2xx(x+4)=4`

`2xx(x+4)=20-4`

`2xx(x+4)=16`

`x+4=16:2`

`x+4=8`

`x=8-4`

`x=4`

Answer 3

\(a,32:\left(3\times X-2\right)=8\\ 3\times X-2=32:8=4\\ 3\times X=4+2=6\\ X=\dfrac{6}{3}=2\\ Vậy:X=2\\ ---\\ b,75:\left(X-18\right)=25\\ X-18=75:25=3\\ X=3+18=21\\ Vậy:X=21\\ ---\\ c,\left(15-6\times X\right)\times243=729\\ 15-6\times X=729:243=3\\ 6\times X=15-3=12\\ X=\dfrac{12}{6}=2\\ Vậy:X=2\\ ---\\ d,4\times\left(X-12\right)+9=17\\ 4\times\left(X-12\right)=17-9=8\\ X-12=8:4=2\\ X=2+12=14\\ Vậy:X=14\\ ---\\ e,20-2\times\left(X+4+4\right)=4\\ 2\times\left(X+4\right)=20-4=16\\ X+4=16:2=8\\ X=8-4=4\\ Vậy:X=4\)

Answer 4

`# \text {04th5.}`

`a,`

`32 \div (3x - 2) = 8`

`=> 3x - 2 = 32 \div 8`

`=> 3x - 2 = 4`

`=> 3x = 6`

`=> x = 6 \div 3`

`=> x = 2`

Vậy, `x = 2`

`b,`

`75 \div (x - 18) = 25`

`=> x - 18 = 75 \div 25`

`=> x - 18 = 3`

`=> x = 3 + 18`

`=> x = 21`

Vậy, `x = 21`

`c,`

`(15 - 6x) * 243 = 729`

`=> 15 - 6x = 729 \div 243`

`=> 15 - 6x = 3`

`=> 6x = 12`

`=> x = 12 \div 6`

`=> x = 2`

Vậy, `x = 2`

`d,`

`4 * (x - 12 ) + 9 = 17`

`=> 4(x - 12) = 17 - 9`

`=> 4(x - 12) = 8`

`=> x - 12 = 2`

`=> x = 2 + 12`

`=> x = 14`

Vậy, `x = 14`

`e,`

`20 - 2(x + 4) = 4`

`=> 2(x + 4) = 20 - 4`

`=> 2(x + 4) = 16`

`=> x + 4 = 16 \div 2`

`=> x + 4 = 8`

`=> x = 8 - 4`

`=> x = 4`

Vậy, `x = 4.`