Extra Questions for Class 7 Maths Chapter 4: Expressions Using Letter-Numbers – HOTS

Fresh HOTS (Higher Order Thinking Skills) practice questions for Class 7 Maths Chapter 4 “Expressions Using Letter-Numbers”, designed to test deeper understanding beyond the textbook exercises. These Class 7 Mathematics Chapter 4 important questions are handy for last-minute exam practice.

Q1.

Simplify: 5x − 3(2x − 4) + 7

Answer: 5x − 6x + 12 + 7 = −x + 19

Q2.

If a = 3 and b = −2, evaluate 4a − 3b + 2ab.

Answer: 4(3) − 3(−2) + 2(3)(−2) = 12 + 6 − 12 = 6

Q3. Assertion-Reason

Assertion (A): The expression 3x + 2y has 2 terms.
Reason (R): Terms in an algebraic expression are separated by + or − signs.

Answer: Both A and R are true, and R correctly explains A.

Q4.

A shopkeeper sells notebooks at Rs. 25 each and pens at Rs. 10 each. Write an expression for the total cost of n notebooks and p pens, then find the cost for 6 notebooks and 4 pens.

Answer: Expression: 25n + 10p. For n=6, p=4: 25(6)+10(4) = 150+40 = Rs. 190

Q5. Spot the error

A student simplified 2(x+3) − (x−1) as “2x+3−x−1 = x+2”. Find and correct the error.

Answer: The student forgot to distribute the 2 to both terms and applied the wrong sign to −(x−1). Correct working: 2x+6−x+1 = x + 7

Q6.

The perimeter of a regular octagon (8 equal sides) with side length s is given by which expression? Find the perimeter when s = 6 cm.

Answer: Perimeter = 8s. For s=6: 8×6 = 48 cm

Q7.

Subtract (5x − 3y + 8) from (9x + 2y − 4).

Answer: (9x+2y−4) − (5x−3y+8) = 9x−5x+2y+3y−4−8 = 4x + 5y − 12

Q8.

A matchstick pattern adds 5 sticks for every new triangle after the first, which uses 3 sticks. Write a general expression for n triangles, and find the number of matchsticks for 12 triangles.

Answer: Expression: 3 + 5(n−1) = 5n − 2. For n=12: 5(12)−2 = 60−2 = 58 matchsticks

Q9.

If the sum of two expressions is 7x − 3y and one of them is 4x + 2y, find the other expression.

Answer: Other expression = (7x−3y) − (4x+2y) = 3x − 5y

Q10.

Sequence puzzle: the nth term of a pattern is 3n − 2. What is the 25th term, and which term equals 100?

Answer: 25th term = 3(25)−2 = 75−2 = 73. For 3n−2=100: 3n=102, n=34th term

NCERT Solutions: Class 7 Maths Chapter 4

Revision Notes: Class 7 Maths Chapter 4 Revision Notes

Written by Satish

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