Question

Find the simplified form of the expression. Give your answer in scientific notation.

(9 x 10 5)(6 x 10 -7)

A. 5.4 x 10 -34

B. 1.5 x 10 -1

C. 5.4 x 10 -1

D. 1.5 x 10 -34

Answer 1

We have that exponents satisfy
`a^x*a^y=a^(x+y)`
Now we get:
`(9*10^5)(6*10^(-7))=9*6*10^5*10^(-7)` by associativity of multiplication.
This is equal to:
`54*10^(5+(-7))=54*10^(-2)` by the property we stated above, for a=10. Scientific notation requires that the coeeficient in fron tof the power of 10 is between 1-10 and thus since 54=10*5.4, we have that the expression is equal to: 5.4*10*
`10^(-2)`=
`5.4*10^(-1)`. Hence the correct answer is C