Q1.Solve the following by using appropriate properties.
a) [3/5 + 3/4 - 2/5 - 1/4]
b) [7/8 × 5/6 + 1/6 × 7/8]
c) [22 ÷ 1/22 + 5]
Q2. Find the product
a) reciprocal of 1 and 1/2
b) 17/5 ÷ 5/17 + 6 × 1/3
Answers
Step-by-step explanation:
-2/3 * 3/5 + 5/2 – 3/5 * 1/6
= -2/3 * 3/5 – 3/5 * 1/6 + 5/2 [Using associative property]
= 3/5 * (-2/3 – 1/6) + 5/2 [Using distributive property]
= 3/5 * {(-4 - 1)/6} + 5/2 [LCM (3, 2) = 6]
= 3/5 * (-5/6) + 5/2
= -3/6 + 5/2
= -1/2 + 5/2
= (-1 + 5)/2
= 4/2
= 2
(ii) 2/5 * (3/-7) – 1/6 * 3/2 + 1/14 * 2/5
= 2/5 * (-3/7) + 1/14 * 2/5 – 1/6 * 3/2 [Using associative property]
= 2/5 * (-3/7 + 1/14) – 1/2 * 1/2 [Using distributive property]
= 2/5 * {(-6 + 1)/14} – 1/4 [LCM (7, 14) = 14]
= 2/5 * (-5/14) – 1/4
= -1/7 – 1/4
= (-4 -7)/28 [LCM (7, 4) = 28]
= -11/28
Question 2:
Write the additive inverse of each of the following:
(i) 2/8 (ii) -5/9 (iii) -6/-5 (iv) 2/-9 (v) 19/-6
Answer:
We know that additive inverse of a rational number a/b is (-a/b) such that a/b + (-a/b) = 0
(i) Additive inverse of 2/8 = -2/8
(ii) Additive inverse of -5/9 = 5/9
(iii) -6/-5 = 6/5
Additive inverse of 6/5 = -6/5
(iv) 2/-9 = -2/9
Additive inverse of -2/9 = 2/9
(v) 19/-6 = -19/6
Additive inverse of -19/6 = 19/6