X + y = 1,000

0.06x = 0.04y

If:

x + y = 1000

then:

y = 1000 - x

We can plug that into the other equation to solve for a value of x.

0.06x = 0.04y

0.06x = 0.04 (1000-x)

0.06x = 40-0.04x

0.1x = 40

x = 400

We can then solve for y:

y = 1000 - 400

y = 600

Therefore, x = 400 and y = 600.