ANSWER
A.
[tex]7.13 \times {10}^{ 7} [/tex]
EXPLANATION
The expression given to us is,
[tex](2.3 \times {10}^{ - 5} )(3.1 \times {10}^{12} )[/tex]
We have to do the multiplication in standard form
[tex](2.3 \times {10}^{ - 5} )(3.1 \times {10}^{12} ) = 2.3 \times 3.1 \times {10}^{ - 5} \times {10}^{12} [/tex]
We now multiply the first two numbers and simplify the last two index numbers using the laws of exponents to obtain,
[tex](2.3 \times {10}^{ - 5} )(3.1 \times {10}^{12} ) = 7.13 \times {10}^{ - 5 + 12} [/tex]
We simplify to get,
[tex](2.3 \times {10}^{ - 5} )(3.1 \times {10}^{12} ) = 7.13 \times {10}^{ 7} [/tex]
Therefore the correct answer is A.
