10. Shade the following regions.

a)

b)

a) Shade in A union B one way

and A union C the other.

Put them both together

and the cross-hatched region looks like

b) Shade in A one way

Shade in B intersect C the other.

Put them together.

The union is the region which is shaded one way or the other.

We see that these two sets are the same. Unions distribute across intersections