Question

tìm x bt

Answer 1

`c) 3-x =-21 -(-9)`

`=> 3-x = -21 +9 `

`3-x=-12`

`=> x = 3-(-12)=3+12 =15`

`_________`

`-12-x-(-19)=0`

`<=> -12 -x +19=0`

`=> 7-x =0`

`=> x=7-0 =7`

`_________`

`46-x=-21+(-87)`

`=> 46-x =-21 -87 =-108`

`=> x = 46 -(-108) = 46+108`

`x =154`

Answer 2

`3-x=-21-(-9)`

`3-x=-21+9`

`3-x=-12`

`x=3-(-12)`

`x=3+12`

`x=15`

_______________

`-12-x-(-19)=0`

`-12-x+19=0`

`-12-x=0-19`

`-12-x=-19`

`x=-12-(-19)`

`x=-12+19`

`x=7`

________________________

`46-x=-21+(-87)`

`46-x=-21-87`

`46-x=-108`

`x=46-(-108)`

`x=46+108`

`x=154`