evaluate the expressions. and write your answer in scientific notation

Question

1. (4.2x10²) (4.2x10⁵)

 

2. (2.5x10^-2)⁴

 

3. 9.6x10²/3.2x10⁵

Answer 1

To do problems like these you regroup the factors, use the properties of exponents to do the multiplication or division, and then convert the answer to scientific notation.  I'll show you how to do 2. 

 

(2.5x10^-2)⁴ = 2.5⁴ x (10^-2)⁴  

                 = 39.0625 x 10^-8  

                 = (3.90625x10¹)x10^-8

                 = 3.90625x10^-7