Page 34 - Start Up Mathematics_8 (Non CCE)

Answer in One Word or a Line

1. What do you mean by the absolute value of a rational number?
2. Is multiplication of rational numbers distributive over subtraction?
3. How many rational numbers exist between any two given numbers?
4. Divisibility of rational numbers by which number is not defined?

let’s evaluate

−7 16  − 5  −3 3 7 9  −13  13
1. Simplify: (a) + (b) 3 +   (c) + + + +   +
26 39  7  10 −20 15 −10  20  15
2. Verify that x + (y + z) = (x + y) + z for:
7 −4 2 3 −13 −7 −2 2
(a) x = , y = , z = (b) x = , y = , z = (c) x = , y = 3, z =
3 5 5 5 15 3 7 3
1 −3 −3  2
− 
3. Subtract the sum of and from the additive inverse of −   .
4 8 8  7 
−8 29
4. From what number should be subtracted to get ?
21 63
p
5. Simplify and write the result in the form q .

 7 5   1 3   4 13   1 1   − 15 7   1 
(a)  2 × 3  +  6 × 2   −   3 × 8  (b)  4 × 2   +   7 × − 18   −   2 × 4 






6. Verify that x × (y + z) = (x × y) + (x × z) for:
4 − 3 12 4 − 6 − 2
(a) x = , y = , z = (b) x = , y = , z =
7 8 − 13 5 7 3
−5 −1
7. Divide the sum of and by their difference.
4 3
−28 −5
8. By what number should be multiplied to get the multiplicative inverse of ?
15 7
9. Represent the following rational numbers on a number line:
−3 8 1 −7
(a) (b) (c) (d)
5 3 3 2
−1 1
10. Find five rational numbers between and .
2 2
Thinking Skills
2 2
1. A bus is moving at the speed of 40 km/h. How far will it travel in 6 hours? If the bus is still at a
3
5
2
distance of 10 km from the final destination, how far is the final destination from the starting point?
3
3 2
2. If of a number exceeds its by 44, find the number.
5 7
2
3. Which is longer and by how much, perimeter of a square of side 4 m or perimeter of a rectangle with
3
1 2
length 5 m and breadth 3 m?
5 5

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