Let us say that:
x = mass from Earl Grey Tea
y = mass from Orange Pekoe Tea
So that:
x + y = 600
and that:
6 x + 4 y = 4.5 * 600
6 (600 – y) + 4 y = 2700
3600 – 6y + 4y = 2700
-2y = -900
y = 450 pounds
x = 600 – 450 = 150 pounds
Answer:
Earl Grey Tea = 150 pounds
Orange Pekoe Tea = 450 pounds