Answer:
2.391 × 10³⁰
Explanation:
3 × 10⁵ times means that we have to multiply the mass of the earth 3 × 10⁵ times:
7.97 × 10²⁴ × 3 × 10⁵ =
for the property of the multiplication we can "divide" the multiplication:
7.97 × 3 (we just multiply)
10²⁴ × 10⁵ (we apply the powers' properties)
23.91 × 10²⁹
Standard forms only accepts numbers from 1 to 9, so we have to correct this result by moving the point one place on the left:
2.391 × 10³⁰