Behold, a see saw!

Suppose that a group of birdsequals a group of pigs in mass.

Here are their individual masses.How heavy is one red angry bird?

What if we removed some weight?

What if we removed some weight?

What if we removed some weight?

What if we removed some weight?

What if we removed some weight?

What if we removed some weight?2x = 8x = 4

One red angry bird has a mass of 4.