Respuesta :

Subtract 19 from both sides
-3x=2+x

Subtract x from both sides
-4x=2

Divide both sides by -4
x=-1/2

Final answer: x=-1/2
19-3x=21+x
Add 3x to both sides. 
19-3x+3x=21=x+3x
19=21+4x
Subtract 21 from both sides.
19-21=21+4x-21
-2=4x
Divide both sides by 4.
-1/2=x

Hope this hleped!