class 7 maths ex 1.2 solutions Chapter 1 Integers
This page contains detailed and easy-to-understand Class 7 Maths Ex 1.2 Solution for students looking to practice and revise Chapter 1: Integers. If you’re searching for Ex 1.2 Class 7 Maths answers that follow the NCERT pattern, you’re in the right place. Our step-by-step solutions are based on the NCERT Ex 1.2 Maths Solution ch 1 Integers to help you score full marks and build a strong foundation in Maths.
Exercise 1.2 Class 7 Maths | Integers
1. Find each of the following products:
(a) 3 × (–1)
(b) (–1) × 225
(c) (–21) × (–30)
(d) (–316) × (–1)
(e) (–15) × 0 × (–18)
(f) (–12) × (–11) × (10)
(g) 9 × (–3) × (– 6)
(h) (–18) × (–5) × (– 4)
(i) (–1) × (–2) × (–3) × 4
(j) (–3) × (–6) × (–2) × (–1)
(a) 3 × (–1)
Solution:
Multiplying a positive number by a negative number results in a negative number.
3×(–1)=–3
Answer: –3
(b) (–1) × 225
Solution:
Multiplying a negative number by a positive number results in a negative number.
(–1)×225=–225
Answer: –225
(c) (–21) × (–30)
Solution:
Multiplying two negative numbers results in a positive number.
(–21)×(–30)= 21 × 30
= 21 × 3 × 10
= 63 × 10
= 630
Answer: 630
(d) (–316) × (–1)
Solution:
Multiplying two negative numbers results in a positive number.
(–316)×(–1)=316
Answer: 316
(e) (–15) × 0 × (–18)
Solution:
Any number multiplied by zero is zero.
(–15)×0×(–18)=0
Answer: 0
(f) (–12) × (–11) × 10
Solution:
First, multiply the two negative numbers:
(–12)×(–11)=132
Then, multiply the result by 10:
132×10=1320
Answer: 1320
(g) 9 × (–3) × (–6)
Solution:
First, multiply 9 by –3:
9×(–3)=–27
Then, multiply the result by –6:
(–27)×(–6)=162
Answer: 162
(h) (–18) × (–5) × (–4)
Solution:
First, multiply –18 by –5:
(–18)×(–5)=90
Then, multiply the result by –4:
90×(–4)=–360
Answer: –360
(i) (–1) × (–2) × (–3) × 4
Solution:
Multiply –1 by –2:
(–1)×(–2)=2
Multiply the result by –3:
2×(–3)=–6
Finally, multiply the result by 4:
(–6)×4=–24
Answer: –24
(j) (–3) × (–6) × (–2) × (–1)
Solution:
Multiply –3 by –6:
(–3)×(–6)=18
Multiply the result by –2:
18×(–2)=–36
Finally, multiply the result by –1:
(–36)×(–1)=36
Answer: 36
2. Verify the following:
(a) 18 × [7 + (–3)] = [18 × 7] + [18 × (–3)]
(b) (–21) × [(– 4) + (– 6)] = [(–21) × (– 4)] + [(–21) × (– 6)]
(a) 18 × [7 + (–3)] = [18 × 7] + [18 × (–3)]
LHS
= 18 × [7 + (–3)]
= 18 × [ 7 – 3 ]
= 18 × 4
= 72
RHS
= [18 × 7] + [18 × (–3)]
= 126 + (–54)
= 126 – 54
= 72
∴ LHS = RHS
Hence, verified.
(b) (–21) × [(– 4) + (– 6)] = [(–21) × (– 4)] + [(–21) × (– 6)]
LHS
= (–21) × [(–4) + (–6)]
= (–21) × [–10]
= 210
RHS
= (–21) × (–4) + (–21) × (–6)
= 84 + 126
= 210
∴ LHS = RHS
Hence, verified.
3. (i) For any integer a, what is (–1) × a equal to?
Solution: (–1) × a = –a
(ii) Determine the integer whose product with (–1) is
(a) –22
(b) 37
(c) 0
(a) –22
Let the integer be x.
(–1) × x = –22
⇒ x = 22
Answer: 22
(b) 37
Let the integer be x.
(–1) × x = 37
⇒ x = –37
Answer: –37
(c) 0
Let the integer be x.
(–1) × x = 0
⇒ x = 0
Answer: 0
4. Starting from (–1) × 5, write various products showing some pattern to show
(–1) × (–1) = 1.
Solution:
(–1) × 5 = –5
(–1) × 4 = –4 = – 5 + 1
(–1) × 3 = –3 = – 4 + 1
(–1) × 2 = –2 = – 3 + 1
(–1) × 1 = –1 = – 2 + 1
(–1) × 0 = 0 = – 1 + 1
(–1) × (–1) = 1 = 0 + 1
Hope these step-by-step solutions helped you understand the concepts of integers better. All the questions from Ex 1.2 Class 7 Maths have been solved in a clear and simple way to make your learning easier. These NCERT Class 7 Maths Ex 1.2 Solutions are designed to match your textbook and help you score full marks in exams. Keep practicing to strengthen your basics!