Question

five expressions which are not polynomials with justification

Answer 1

(1) 3x⁻⁴+4y² isn't a polynomial, as there is a negative power of x, .e. -4.
(2) 5/x isn't a polynomial, as again 5/x= 5* 1/x=5x⁻¹, which is a negative power.
(3) 4√y-3∛5x isn't a polynomial, as √y=$y^{ \frac{1}{2} }$ , which is a fractional power.
(4) $7 tp^{ \frac{4}{9} } -6t$ isn't a polynomial, as p has a fractional power.
(5) 67/ab²c³ isn't a polynomial, as power of a= -1, b= -2 an c= -3, when acted as neumerators.