Chapter 2 - Solving Equations - 2-2 Solving Two-Step Equations - Practice and Problem-Solving Exercises - Page 91: 30

x=12

We need to get the x alone. We need to use multiplication to cancel out division, so we multiply both sides by 2 to get that x+3=15. We now cancel out the addition by subtracting 3 on both sides, giving us a final answer of x=12. We plug 12 in for x and confirm that our answer is, indeed, correct.