X = low-energy lamp
y = high-energy lamp
1) 4x + 5y
2) 120= 4x + 5y
The answer is 0.15290519877
The easier way is online games.
< W and < X are congruent....so they are equal.....so if their sum is 121....just divide by 2 for ur answer
121/2 = 60.5.....so < W = 60.5 and < X = 60.5