Classify the following as linear, quadratic and cubic polynomials

Classify the following as linear, quadratic and cubic polynomials:
(i) x² + x          (ii) x – x³            (iii) y + y² + 4             (iv) 1 + x         (v) 3t               (vi) r²  
Solution: (i) x² + x         
Highest power of x is 2 so it is a quadratic polynomials
(ii) x – x³        
Highest power of x is 3 so it is cubic polynomial
(iii) y + y² + 4            
Highest power of y is 2 so it is quadratic polynomial
(iv) 1 + x        
Highest power of x is 1 so it is linear polynomial
(v) 3t
Highest power of t is 1 so it is linear polynomial
(vi) r²  
Highest power of t is 2 so it is quadratic polynomial
(vii) 7x³
Highest power of x is 3 so it is cubic polynomial