Ex 9.1, 9 - Which is greater in each (i) 2/3, 5/2 (ii) -5/6, -4/3

Ex 9.1, 9 - Chapter 9 Class 7 Rational Numbers - Part 2
Ex 9.1, 9 - Chapter 9 Class 7 Rational Numbers - Part 3 Ex 9.1, 9 - Chapter 9 Class 7 Rational Numbers - Part 4 Ex 9.1, 9 - Chapter 9 Class 7 Rational Numbers - Part 5 Ex 9.1, 9 - Chapter 9 Class 7 Rational Numbers - Part 6 Ex 9.1, 9 - Chapter 9 Class 7 Rational Numbers - Part 7 Ex 9.1, 9 - Chapter 9 Class 7 Rational Numbers - Part 8 Ex 9.1, 9 - Chapter 9 Class 7 Rational Numbers - Part 9 Ex 9.1, 9 - Chapter 9 Class 7 Rational Numbers - Part 10 Ex 9.1, 9 - Chapter 9 Class 7 Rational Numbers - Part 11 Ex 9.1, 9 - Chapter 9 Class 7 Rational Numbers - Part 12 Ex 9.1, 9 - Chapter 9 Class 7 Rational Numbers - Part 13

  1. Chapter 9 Class 7 Rational Numbers
  2. Serial order wise

Transcript

Ex 9.1, 9 Which is greater in each of the following: (i) 2/3, 5/2 2/3, 5/2 Here, denominator is different So, we make denominator same Common denominator = L.C.M of 2 & 3 = 2 ร— 3 = 6 So, 2/3 = 5/2 = Therefore, 4/6 < 15/6 i.e. 2/3 < 5/2 So, ๐Ÿ“/๐Ÿ is greater Ex 9.1, 9 Which is greater in each of the following: (ii) (โˆ’5)/6, (โˆ’4)/3 (โˆ’5)/6, (โˆ’4)/3 Since both numbers are negative, We ignore the signs 5/6 & 4/3 We compare these two numbers Since denominator is different, we make it same. Common denominator = L.C.M of 3 & 6 = 2 ร— 3 = 6 So, 5/6 = 4/3 = Therefore, 5/6 < 8/6 i.e. 5/6 < 4/3 Multiplying โ€“1 both sides 5/6 ร— โ€“1 > 4/3 ร— โ€“1 (โˆ’5)/6 > (โˆ’4)/3 So, (โˆ’๐Ÿ“)/๐Ÿ” is greater. Ex 9.1, 9 Which is greater in each of the following: (iii) (โˆ’3)/4, 2/(โˆ’3) (โˆ’3)/4, 2/(โˆ’3) i.e. (โˆ’3)/4, (โˆ’2)/3 Since both numbers are negative, We ignore the signs 3/4 & 2/3 We compare these two numbers Common denominator = L.C.M of 4 & 3 = 2 ร— 2 ร— 3 = 12 So, 3/4 = 2/3 = Therefore, 9/12 > 8/12 i.e. 3/4 > 2/3 Multiplying โ€“1 both sides 3/4 ร— โ€“1 < 2/3 ร— โ€“1 (โˆ’3)/4 < (โˆ’2)/3 So, (โˆ’๐Ÿ)/๐Ÿ‘ is greater. (โˆ’1)/4, 1/4 Since positive number is always greater than negative number. 1/4 & (โˆ’1)/4 So, ๐Ÿ/๐Ÿ’ is greater Ex 9.1, 9 Which is greater in each of the following: (v) โˆ’3 2/7, โˆ’3 4/5 โ€“3 2/7, โ€“3 4/5 โ€“3 ๐Ÿ/๐Ÿ• = โ€“ (3+2/7) = โ€“ ((3 ร— 7 + 2)/7) = โ€“ ((21 + 2)/7) = (โˆ’23)/7 โ€“3 ๐Ÿ’/๐Ÿ“ = โ€“ (3+4/5) = โ€“ ((3 ร— 5 + 4)/7) = โ€“ ((15 +4)/5) = (โˆ’19)/5 So, we have to compare (โˆ’23)/7 & (โˆ’19)/5 Since both numbers are negative, We ignore the signs. 23/7 & 19/5 Comparing these two numbers Since denominator is different, We make same Common denominator = L.C.M of 5 & 7 = 5 ร— 7 = 35 So, 23/7 = 19/5 = Therefore, 115/35 < 133/35 i.e. 23/7 < 19/5 Multiplying โ€“1 both sides 23/7 ร— โ€“1 < 19/5 ร— โ€“1 (โˆ’23)/7 > (โˆ’19)/5 โ€“3 2/7 > โ€“3 4/5 So, โ€“3 ๐Ÿ/๐Ÿ• is greater.

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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 10 years. He provides courses for Maths and Science at Teachoo.