Which numbers should be multiplied to obtain 175^2 − 124^2?

Can someone check if i did this correct. it’s number 4 if you’re wondering.

According to the 2008 u.s. census, california had a population of approximately 4 × 10^7 people and florida had a population of approximately 2 × 10^7 people. which of the following is true? a. the population of california was approximately two times the population of florida. b. the population of florida was approximately twenty times the population of california. c. the population of florida was approximately two times the population of california. d. the population of california was approximately twenty times the population of florida.

When solving a logarithm equation, how do you find the missing variable ?