`(x-47)-115=0`
`x-47=0+115`
`x-47=115`
`x=115+47`
`x=162`
____________________________________
`315+(146-x)=401`
`146-x=401-315`
`146-x=86`
`x=146-86`
`x=60`
_____________________________________
`(3x-15).7=42`
`3x-15=42:7`
`3x-15=6`
`3x=6+15`
`3x=21`
`x=21:3`
`x=7`
____________________________________
`(8x-16).(x-5)=0`
`=>8x-16=0`
`8x=0+16`
`8x=16`
`x=16:8`
`x=2`
`=>x-5=0`
`x=0+5`
`x=5`
________________________________
`250:(10-x)=25`
`10-x=250:25`
`10-x=10`
`x=10-10`
`x=0`
______________________________
`3x-2018:2=23`
`3x-1009=23`
`3x=23+1009`
`3x=1032`
`x=1032:3`
`x=344`
Bài 3:
a: =>x-47=115
=>x=162
b: =>146-x=401-315=86
=>x=60
a) (x - 47) - 115 = 0
x - 47 = 0 + 115
x - 47 = 115
x = 115 + 47
x = 162
b) 315 + (146 - x) = 0
315 + 146 - x = 0
361 - x = 0
x = 361 - 0
x = 361
c) (3 . x - 15) . 7 = 42
3 . x - 15 = 42 : 7
3 . x - 15 = 6
3 . x = 6 + 15
3 . x = 21
x = 21 : 3
x = 7
d) (8 . x - 16)(x - 5) = 0
8 . x - 16 = 0 hoặc x - 5 = 0
*) 8 . x - 16 = 0
8 . x = 0 + 16
8 . x = 16
x = 16 : 8
x = 2
*) x - 5 = 0
x = 0 + 5
x = 5
Vậy x = 2; x = 5
