x = amount the baby eats
x+15 = amount the mother eats
mother + baby = 39 pounds total
(x+15) + (x) = 39
2x+15 = 39
2x = 39-15
2x = 24
x = 24/2
x = 12 pounds is the amount the baby eats
x+15 = 12+15 = 27 pounds is the amount the mother eats
As a check: 12+27 = 39 so the answer is confirmed
Answer: The baby panda eats 12 pounds of bamboo each day.