Question

Amanda is adding the numbers below.

3.7 x 10^20 + 4.45x10^20
What is the sum written in scientific notation?

Answer 1

add 3.7 and 4.45 make sure to change it back to standard you'll get 815000000000000000000. move decimal between first and second digit which means you moved it to the left 18 times and your answer will be 8.15 x 10 ^18 I hope its right :( please don't judge if wrong :((( lol

Answer 2

Answer: 8.15 x 10²⁰

Explanation:

In order to add or subtract, they must both have the same power - think of the power as "like terms". In this problem they already have the same power (10²⁰) so we don't need to manipulate them to have the same power. We can just add their coefficients (3.7 and 4.45).

3.7 x 10²⁰

+ 4.45 x 10²⁰

8.15 x 10²⁰