Answer: w = 18
Step-by-step explanation: To solve for w in this equation, we want to get w by itself on the left side of the equation.
Since 3 is being subtracted from w, to get w by itself,
we need to add 3 to the left side of the equation.
If we add 3 to the left side, we must also add 3 to the right side.
Notice that on the left side, -3 and +3 cancel
each other out so were simply left with w.
On the right side, 15 + 3 is 18.
So we have w = 18.