Answer:
400 g
Explanation:
Let p represent the mass of the peas & carrots. The scale is balanced when the mass on one side is equal to the mass on the other side.
p + 2(300 g) = 4(250 g)
p = 1000 g -600 g . . . . . subtract 600 g
p = 400 g
The mass of the peas & carrots is 400 grams.