<span>The question is asking us to calculate how many envelopes are there in 7 packages if there are 75 in a package. For example: in 1 package there are 75 envelopes. In 2 packages there are 7 * 2 = 150 envelopes. In general, formula is : 75 * n, where n is the number of packages. Therefore, we will multiply 75 by 7. 75 * 7 = 525. Answer: B ) 525 envelopes.</span>
In order to find the answer, we need to convert the scientific notation into standard notation and then simplify by subtracting the decimals. Then we convert the standard notation back into scientific notation.