Question

tìm x
x - 86= (243 - x) - 15

(x - 16) - 19= (20 - 3) - (18 + x)

Answer 1

Lời giải:

$x-86=(243-x)-15$

$x-86=243-x-15=228-x$

$x+x=228+86$

$2x=314$

$x=157$

$(x-16)-19=(20-3)-(18+x)$

$x-16-19=17-18-x$

$x-35=-1-x$

$x+x=35+(-1)$

$2x=34$

$x=17$

 

Answer 2

`x - 86 = (243 - x ) - 15`

`=> x -  86 =243 - x - 15`

`=> x +x = 243 - 15 + 86`

`=> 2x = 314`

`=> x = 314 : 2`

`=> x = 157`

________________________

`(x - 16) - 19 = (20 - 3) - (18 + x)`

`=> x - 16 - 19 = 17 - 18 - x`

`=> x + x = 17 - 18 + 16 + 19`

`=> 2x = 34`

`=> x= 34 : 2`

`=> x = 17`