The grasshopper, the frog and the mouse had a jumping contest. The grasshopper jumped w inches. The grasshopper jumped x inches farther than the frog and the mouse jumped y inches lesser than the frog. How much farther did the grasshopper jump than the mouse?
Let's denote the jump of the grasshopper by g, the jump of the frog by f and the jump of the mouse by m.

g = w

g = f + x

m = f - y

Now we can solve for f.

f = g - x

f = m + y

g - x = m + y

g - m = x + y

Therefore, the answer (symbolic expression) is: 

x + y