Simplify (3.9 × 10−2)(5.13 × 10−10). Write the final answer in scientific notation.

Question

a) 20.007 × 10−12

b) 2.0007 × 10−11

c) 20.007 × 1020

d) 2.0007 × 1020

Answer 1

To simplify the expression, we multiply the coefficients and add the exponents of the powers of 10.

(3.9 × 10^(-2))(5.13 × 10^(-10)) = (3.9)(5.13) × 10^((-2)+(-10)) = 20.007 × 10^(-12)

The final answer in scientific notation is therefore 20.007 × 10^(-12), which is equivalent to (a) 20.007 × 10^(-12).