Question

evaluate each expression. express your answer in scientific notation.
(7) (1.1×10^4)(2.5×10^9)
(8) (3.4×10^4)(2.8×10^5)

Explanation:

Step1: Multiply the non - exponential parts

Multiply the numbers in front of the powers of 10. For (7) $(1.1\times10^{4})(2.5\times10^{9})$, we have $1.1\times2.5 = 2.75$.

Step2: Add the exponents of 10

Using the rule $a^{m}\times a^{n}=a^{m + n}$, for $10^{4}\times10^{9}$, we get $10^{4 + 9}=10^{13}$.

Step3: Combine the results

The result is $2.75\times10^{13}$.
For (8) $(3.4\times10^{4})(2.8\times10^{5})$, first $3.4\times2.8=9.52$. Then $10^{4}\times10^{5}=10^{4 + 5}=10^{9}$. The result is $9.52\times10^{9}$.

Answer:

(7) $2.75\times10^{13}$
(8) $9.52\times10^{9}$