Respuesta :

x+3=15   =   x+3-3=15-3
you need to isolate the variable... x
so now it is x=12 
hope that helped!

x+3=15

Subtract 3 from both sides

x+3-3=15-3

x=12


I hope that's help !


Check my answer

Replace x by 12

12+3=15

15=15


So... Yes my answer is correct !