Your bases are like: they are both x. When you multiply like bases with exponents, you add the exponents together to get the new power. But you can't add those til you get a common denominator. That's 20. So your problem looks like this: [tex] x^{ \frac{15}{20} } * x^{ \frac{4}{20} } [/tex] which gives you [tex] x^{ \frac{19}{20} } [/tex]. That's your answer!
