Your first impulse might be to cross multiply, but doing so would actually complicate the
question unnecessarily. Notice that the fractions on both sides have the same numerator,
- So the numerator is irrelevant. If the two fractions are equal and they have the same
numerator, then they must have the same denominator, so just write an equation reflecting
as much:
7 . A
Express everything as powers of 5:
The left side of the equation is the product of powers with the same base, so just add the
exponents:
Now the two sides of the equation are powers with the same base, so you can just set the
exponents equal to each other:
