Question

i need help please.

Answer 1

It's the fourth choice :)
You basically combine like terms.
So, the 3 times the 5, \[x ^{3}\times x\] and\[y ^{2} \times y ^{-1}\]
When multiplying exponents, you add the numbers up top.
So it'll look like
\[15x ^{4}y \]
Hope this helps :)