5.9 × 10^24 = 5,900,000,000,000,000,000,000,000 minus 13,000,000,000,000,000,000,000 equals 5,887,000,000,000,000,000,000,000 kg which is the amount greater that Earth's mass is. you could write this problem as 5.9 × 10^24 - 13 × 10^21 = 5.887 × 10^21
Simply use the formula they give you. For question 6, 4 is the radius. So the area of the circle is 4pi. Now for seven you do the same thing, but they gave you the diameter instead and it’s a half circle. So try that one on your own. Let me know if you get stuck
