Which expression are polynomial can be more than one answer

and 6y²+5x

Step-by-step explanation:

Polynomials are algebraic expressions involving one, or even more than one variables raised to any power summing each other. Generally speaking, in other words an one variable Polynomial is

So a multivariate polynomial expression are and 6y²+ 5x.

Because in the other options:

We have a Radical of an Irrational number times x (2nd option) what does not configure a polynomial.

And a Polynomial Quotient with a variable on the denominator, described by:

Like the last option:

V - the crew rowing rate,
u - rate of the current.
Downstream:  v + u = 13.5/1.5 = 9 mph
Upstream :      v - u = 13.5/4.5 = 3 mph
u = 9 - v
v - ( 9 - v ) = 3
v - 9 + v = 3
2 v = 12
v = 6 mph,   u = 9 - 6 = 3 mph
the crew`s rowing rate is 6 mph and the rate of the current is 3 mph.