To solve for w in the equation 215 = 116 - w, you can isolate w by performing the following steps:
1. First, subtract 116 from both sides of the equation to get w on one side:
215 - 116 = 116 - 116 - w
This simplifies to:
99 = -w
2. Now, to solve for w, you need to get rid of the negative sign. Divide both sides by -1:
(-1)(99) = (-w)(-1)
This simplifies to:
-99 = w
So, the solution to the equation is:
w = -99