multiplying fractions and simplifying

Question

9v to the 4th power over 4v times 3 over 4

 

y squared -81 over y squared times y squared -9y over y squared +y-90

can anyone tell me an easy way to figure these types of problems out? Thanks for any help

Answer 1

9v⁴/(4v×¾)=9v⁴/(3v)=3v³

(+y-90)(y²-81)/(y²(y²-9y))=(y-90)(y-9)(y+9)/(y³(y-9))=(y-90)(y+9)/y³, which can also be written (y²-81y-810)/y³.