Answer:
To solve for x, we need to isolate x on one side of the equation. We can do this by subtracting 3 from both sides of the equation:
4x + 3 - 3 = 15 - 3
Simplifying:
4x = 12
Now we can solve for x by dividing both sides of the equation by 4:
4x/4 = 12/4
Simplifying:
x = 3
Therefore, x = 3 is the solution to the equation 4x + 3 = 15.