Polynomial & its types | Algebraic Expressions | Assessment | English | Grade 7

Which of the following is a binomial?

• a

• a² + 2

• a² ÷ b

• a + 2a

Answer explanation

An expression which contains two unlike terms is called a binomial. In Option 1, there is only one term. Hence it is a monomial. In Option 2, there are two unlike terms. Hence it is a binomial. In Option 3, we can write a² ÷ b as a²/b which is a monomial. In Option 4, a + 2a = 3a which is a monomial. Hence, option 2 is correct.

Which of the following is a trinomial?

• ab + bc × yz

• 5a²y × 2 × pqz

• a² - b + 3xyz

• 4y -3y² + 2y

Answer explanation

An expression which contains three terms is called a trinomial. In Option 1, there are two terms ab and bcyz. Hence it is a binomial. In Option 2, there is only one term because 5a²y × 2 × pqz = 10a²ypqz. Hence, it is a monomial. In Option 3, there are three terms a², (-b) and 3xyz. Hence, it is a trinomial. In Option 4, 4y - 3y² + 2y = 6y - 3y² which is a binomial. Hence Option 3 is the right answer.

In the following algebraic expressions identify the expression which is a polynomial. Expression I: mn²r Expression II: m²n² + 3r²q Expression III: 5n² + 3n²r + mn² + 25

• Expression I only

• Expressions II only

• Expressions III only

• Expressions I, II and III

Answer explanation

A polynomial is an expression consisting of one or more terms. Since all expressions contain one or more terms, all expressions are polynomials. Hence, option 4 is correct.

The length of side of a square is a. The expression for the perimeter of the square must be ________.

• a monomial

• a binomial

• a trinomial

• none of the above

Answer explanation

The perimeter of a square = 4 x length of side = 4a Since the expression for the perimeter of the square contains only one term hence it is a monomial. Therefore, option 1 is correct.

Shalini went to market to buy some fruits. She purchased x kg apples at a rate of ₹ 80 per kg and 3 kg oranges at a rate of ₹ y per kg. The expression for the total cost of fruits is ________.

• a monomial

• a binomial

• a trinomial

• none of the above

Answer explanation

Total cost of x kg apples at a rate of ₹ 80 per kg = 80x Total cost of 3 kg oranges at a rate of y per kg = 3y Total cost = 80x + 3y This is a binomial as it contains two terms 80x and 3y. Hence, option 2 is correct.