Question

10x+3=15

Answer 1

your job is to isolate x
10x+3= 15

we want to get rid of the 3 from the right side so we subtract 3 to both sides
10x +3-3 = 15-3
10x=12

now we can isolate x by dividing 10 to both sides

10/10 x = 12/ 10

and you get
x = 12/10, simplify that if you want

remember when doing these problems, if you ever do something to one side, you have to do the same thing to the other