Home | | Maths 7th Std | Exercise 3.3 (Simple linear equations)

# Exercise 3.3 (Simple linear equations)

7th Maths : Term 1 Unit 3 : Algebra : Simple linear equations : Exercise 3.3 : Fill in the blanks, Say true or false, Find the value of the following, Objective type questions, Text Book Back Exercises Questions with Answers, Solution

Exercise 3.3

1. Fill in the blanks.

(i) An expression equated to another expression is called equation.

(ii) If a = 5, the value of 2a + 5 is 2(5) + 5 = 10 + 5 = 15.

(iii) The sum of twice and four times of the variable x is 2x and 4x.

2. Say True or False.

(i) Every algebraic expression is an equation (False)

(ii) The expression 7x + 1 can not be reduced without knowing the value of x(True)

(iii) To add two like terms, its coefficients can be added. (True)

3. Solve:

(i) x + 5 = 8 (ii) p − 3 = 7 (iii) 2x = 30 (iv) m/6 = 5 (v) 7x + 10 = 80

(i) x + 5 = 8

x + 5 – 5 = 8 – 5

x = 3

(ii) p – 3 =7

p – 3 + 3 = 7 + 3

p = 10

(iii) 2x = 20

2x / 2 = 20 / 2

x = 10

(iv) m / 6 = 5

[m/6] × 6 = 5 × 6

m = 30

(v) 7x + 10 = 80

7x + 10 – 10 = 80 – 10

7x = 70

7x / 7 = 70 / 7

x = 10

4. What should be added to 3x + 6y to get 5x + 8y?

5x + 8y – (3x + 6y)

5x + 8y – 3x – 6y

5x – 3x + 8y– 6y

(5 – 3) x + (8 – 6)y

2x + 2y

2x + 2y should be added to 3x + 6y to get 5x + 8y

5. Nine added to thrice a whole number gives 45. Find the number.

Let the whole number be x

3x + 9 = 45

3x + 9 – 9 = 45 – 9

3x = 36

3 / 3 x = 36 / 3

x = 12

6. Find two consecutive odd numbers whose sum is 200.

Let the two consecutive odd numbers

be x, x + 2

Their sum x + x + 2 = 200

2x + 2 = 200

2x + 2 – 2 = 200 – 2

2x = 198

2x / 2 = 198 / 2

x = 99

x + 2 = 99+ 2 =101

The two consecutive odd numbers are 99, 101.

7. The taxi charges in a city comprise of a fixed charge of 100 for 5 kms and 16 per km for every additional km. If the amount paid at the end of the trip was 740 find the distance travelled.

The distance travelled = x km

Fixed charge for 5 km = ₹ 100

Remaining distance = (x – 5) km

Charge for every additional km = ₹ 16

Charge for (x – 5)km = ₹ (x – 5) 16

Given (x – 5) 16 = ₹ 740 – 100

= ₹ 640

(x – 5) x 16 / 16 = 640 / 16 = 40

x – 5 = 40

x – 5 + 5 = 40 + 5

x = 45

The distance travelled = 45 km

Objective type questions

8. The generalization of the number pattern 3, 6, 9, 12,… is

(i) n

(ii) 2n

(iii) 3n

(iv) 4n

9. The solution of 3x + 5 = x + 9 is

(i) 2

(ii) 3

(iii) 5

(iv) 4

10. The equation y + 1 = 0 is true only when y is

(i) 0

(ii) − 1

(iii) 1

(iv) − 2

EXERCISE-3.3

1. (i) equation (ii) 15 (iii) 6x

2. (i) False (ii) True (iii) True

3. (i) x = 3 (ii) p = 10 (iii) x = 15 (iv) m = 30 (v) x = 10

4. 2x+2y

5. x = 12

6. 99 and 101

7. x = 45km

Objective type questions

8. (iii) 3n

9. (i) 2

10. (ii) −1

Tags : Questions with Answers, Solution | Algebra | Term 1 Chapter 3 | 7th Maths , 7th Maths : Term 1 Unit 3 : Algebra
Study Material, Lecturing Notes, Assignment, Reference, Wiki description explanation, brief detail
7th Maths : Term 1 Unit 3 : Algebra : Exercise 3.3 (Simple linear equations) | Questions with Answers, Solution | Algebra | Term 1 Chapter 3 | 7th Maths