**Question:**

Classify the following polynomials as polynomials in one variable, two variables etc.

(i) x2 + x +1

(ii) y3 – 5y

(iii) xy+ yz +zx

(iv) x2 – Zxy + y2 +1

**Solution:**

(i) Polynomial x2+ x+ 1 is a one variable polynomial, because it contains only one variable i.e., x.

(ii) Polynomial y3 – 5y is a one variable polynomial, because it contains only one variable i.e., y.

(iii) Polynomial xy+ yz+ zx is a three variables polynomial, because it contains three variables x, y and z.

(iv) Polynomial x2 – Zxy + y2 +1 is a two variables pplynomial, because it contains two variables x and y.