Step-by-step explanation:
please mark me as brainlest
Answer:
16,425
For future references, I'd say use a calculator for multiplication or calculate on a piece of paper. :)
1 / y^7
Y^-9•y^-8•y^10
= y^10 / y^9•y^8
= y^10 / y^17
= 1 / y^7
7980
900+80+7000=7980
