When multiply two power expressions, that both have the same base, we can simply add the exponents.
For the first image that you provided:
y^(3/4) x y^(1/3) = y^(3/4 + 1/3) = y^(9/12 + 4/12) = y^(13/12)
Let me know if you have any further questions!
Plz mark as brainliest
