Plz me. this is really hard and i really don't get it!

a:

b:

Step-by-step explanation:

For a:

The combined mass is the totaled mass of all the objects.

So that would be

For b:

We need to find how many of the moon-Earth-Pluto combinations are needed to match the mass of the sun.

So, we would calculate the following:

So it would take approximately of the moon-Earth-Pluto combos to match the mass of the sun.

correct answer is infinitely many solutions

step-by-step explanation:

2(2x + 3) = -4 + 2(2x + 5)

solving the above equation:

4x + 6 = -4 +4x +10

combining like terms

4x -4x = -4+10-6

0=0

since both sides are 0=0, we end up into true statement it means it has infinite many solutions.

so correct answer is infinitely many solutions