Solved Exercise for Integers

Integers of Class 7

Solved Questions for Integers

question 7 x (-4) = ?

Solution: Rule I: The product of two integers with other signs is equal to the product of their absolute values with negative sign.

So, 7 x (-4) =-28

question 7 x 12 = ?

Solution: Rule II: The product of two integers with like signs is equal to the product of their absolute values.

So, 7 x 12 = 84

question 5x(10+7) = ?

Solution: By the property :a x (b + c) = ab + ac

5 x (10+7) = 5x10 + 5x7

= 50+35

= 85.

Fill in the blanks:

question (i) (-65) + 12 = ………… + (-65)

question (ii) ……….. x 12 = ………… x (8)

question (iii) 5 – (-12) = ………… (-4) – 6

Solution:

Solution (i) (-65) + 12 = 12 + (-65)

Solution (i) 8 x 12 = 12 x 8

Solution (iii) 5 – (-12) = 27 (-4) -6

question Find the value of : 50945 x89 – (-40596)

Solution: 50945 x 89- (-40596) = 4534105- (-40596)

= 4574701

True False

question 1. The number is not divisible by 2 is known as a prime number.

question 2. The multiplicative identity for integers is -1

question 3. The product of two numbers with opposite sign is always negative.

question 4. The identity property in addition state that we will get the same number when add zero to the number.

question 5. The difference of two numbers with opposite signs is always negative

ANSWERS

Solution 1.False

Solution 2.False

Solution 3.True

Solution 4.True

Solution 5.False

Lets Try

question 1. If a = – 117, b = 83, then [|a| + |b|] × [|a| – |b|] is…………….

question 2. If X = 8, Y = – 5, A = – 9, B = 5, C = 7 and D = – 4, then (X × Y) × [(A + B) + (C – D)] is

(a) – 280

(b) – 380

(c) – 180

(d) – 480

question 3. If the sum of first 6 multiples of 3 is subtracted from the sum of first 10 multiples of 3, then the result is a multiple of…………..

question 4. The absolute value of an integer is either …………….. or ……………….. than the integer, but never ……………….. than the integer.

question 5. The successor of -91 is ………………

Answers:

1. 6800 2. – 280 3. 2,3 4. greater than, equal to, less than 5. -90

question 1. If a = – 117, b = 83, then [|a| + |b|] × [|a| – |b|] is…………….

Solution = (117 + 83) (117 – 83) = 200 × 34 = 6800

question 2. If X = 8, Y = – 5, A = – 9, B = 5, C = 7 and D = – 4, then (X × Y) × [(A + B) + (C – D)] is

Solution X × Y = + 8 × – 5 = – 40, A + B = – 9 + 5 = – 4, C – D = + 7 – (– 4) = 7 + 4 = 11

(X × Y) × [(A + B) + (C – D)] = – 40 × [ – 4 + (11)] = – 40 × [+ 7] = – 280