Sphere 1 has 4 positive charges and sphere 2 has 2 negative charges. what is the charge on each if they are brought together?

The first one with 2+ and the second one with zero.

Explanation:

If you join these two spheres, the one with more quantity of positive charges is going to neutralize the second sphere, in this way, is going to have at the end just 2 positive charges.

The second sphere, since just have 2 negative charges, they are going to be neutralize with 2 positive charges from the first sphere, in this way at the end, is going to have a zero charge.