Im pretty sure the answer is 4 but not 100 percent
Acid A, assuming the two acids have the same pH. The M stands for molarity which is how concentrated a substance is (basically the higher the molarity the more concentrated the acid is). However, pH refers to how acidic a substance is. If the two acids have different levels of acidity, the answer may be different.
3.45x-8.75 is the simplified version:)