Question

Simplify the expression. Write the answer using scientific notation. (9 x 10)^2(2 x 10)^10

A) 1.8 x 10^21
B) 1.8 x 10^13
C) 1.1 x 10^13
D) 1.1 x 10^21

Answer 1

B

Explanation:

To multiply scientific notation, multiply each part of the number.

(9 x 10)^2(2 x 10)^10 = (9*2) * (10^ 2 + 10) = 18 * 10 ^ 12

Since scientific notation can only have a digit in the ones place from 1-9. 18*10^12 becomes 1.8*10^13.

The solution is B.