Question

Under which of the following operations are the polynomials 3x+2 and 4y-11 not closed

Answer 1

Lets check all the choices:

A. subtraction:

(3x+2)-(4y-11)=3x+2-4y+11=3x-4y+13

similarly, (4y-11)-(3x+2)=-3x+4y-13

both are polynomials (of 2 variables)

B. (3x+2)(4y-11)=12xy-33x+8y-22, which is a polynomial

C. (3x+2)+(4y-11)=3x+2+4y-11=3x+4y-9, which is a polynomial

D. 
both $\frac{3x+2}{4y-11}$ and $\frac{4y-1}{3x+2}$ are rational expressions in 2 variables, not polynomials



Answer: D