Class 7 Mathematics

Chapter 12: Algebraic Expressions

NCERT Textbook Questions & Answers

Question 1

Write the algebraic expression for the following:
(a) 5 added to a number x
(b) 3 less than a number y

Answer:

(a)

Step 1: The number is x.
Step 2: 5 added to x means x + 5.

(b)

Step 1: The number is y.
Step 2: 3 less than y means y − 3.

✅ Final Answer: (a) x + 5    (b) y − 3

Question 2

Write the algebraic expression for:
(a) 7 times a number a
(b) Half of a number m

Answer:

(a)

7 times a means 7 × a = 7a

(b)

Half of m means m ÷ 2 = m/2

✅ Final Answer: (a) 7a    (b) m/2

Question 3

Identify the terms, coefficients, and constants in the expression:
4x − 5y + 7

Answer:

Step 1: Identify terms (separated by + or −).

• 4x
• −5y
• 7

Step 2: Identify coefficients.

• Coefficient of x = 4
• Coefficient of y = −5

Step 3: Identify constant.

Constant = 7

✅ Final Answer: Terms: 4x, −5y, 7; Coefficients: 4, −5; Constant: 7

Question 4

Which of the following are like terms?
(a) 3x and 5x
(b) 4a and 4b

Answer:

(a)

3x and 5x have the same variable x. So, they are like terms.

(b)

4a and 4b have different variables. So, they are unlike terms.

✅ Final Answer: (a) Like terms    (b) Unlike terms

Question 5

Write an algebraic expression for:
“10 more than twice a number n”

Answer:

Step 1: Twice of n = 2n
Step 2: 10 more than 2n means 2n + 10

✅ Final Answer: 2n + 10

---

Shaktimatha CBSE Learning
Class 7 Mathematics – Chapter 12
NCERT Textbook Questions & Answers

⬅️ Back to Class 7 Maths Library