Question 4 - Figure it out (Page 42, 43, 44) - Chapter 2 Class 7 - Arithmetic Expressions (Ganita Prakash)

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Question 4 Compare the following pairs of expressions using ‘<’, ‘>’ or ‘=’ or by reasoning. (a) 49 – 7 + 8 49 – 7 + 8 49 – 7 + 8 vs 49 – 7 + 8 These are the same expression Answer: = Question 4 Compare the following pairs of expressions using ‘<’, ‘>’ or ‘=’ or by reasoning. (b) 83 × 42 – 18 83 × 40 – 18 83 × 42 – 18 vs 83 × 40 – 18 Since 42 > 40, and both are multiplied by 83 Thus, LHS > RHS Answer: > Question 4 Compare the following pairs of expressions using ‘<’, ‘>’ or ‘=’ or by reasoning. (c) 145 – 17 × 8 145 – 17 × 6 145 – 17 × 8 vs 145 – 17 × 6 → Subtracting a larger number on LHS (17 × 8 > 17 × 6) Thus, LHS < RHS Answer: < Question 4 Compare the following pairs of expressions using ‘<’, ‘>’ or ‘=’ or by reasoning. (d) 23 × 48 – 35 23 × (48 – 35) 23 × 48 – 35 vs 23 × (48 – 35) Now, → LHS: 1104 – 35 = 1069 → RHS: 23 × 13 = 299 Thus, LHS > RHS Answer: > Question 4 Compare the following pairs of expressions using ‘<’, ‘>’ or ‘=’ or by reasoning. (e) (16 – 11) × 12 –11 × 12 + 16 × 12 Evaluating individually (16 – 11) × 12 = 5 × 12 = 60 –11 × 12 + 16 × 12 = (–11 + 16) × 12 = 5 × 12 = 60 Thus, Both equal Answer: = Question 4 Compare the following pairs of expressions using ‘<’, ‘>’ or ‘=’ or by reasoning. (f) (76 – 53) × 88 88 × (53 – 76) Evaluating individually (76 – 53) × 88 = 23 × 88 88 × (53 – 76) = 88 × (–23) Thus, LHS is positive, RHS is negative Answer: > Question 4 Compare the following pairs of expressions using ‘<’, ‘>’ or ‘=’ or by reasoning. (g) 25 × (42 + 16) 25 × (43 + 15) Evaluating individually 25 × (42 + 16) = 25 × 58 25 × (43 + 15) = 25 × 58 Thus, Both equal Answer: = Question 4 Compare the following pairs of expressions using ‘<’, ‘>’ or ‘=’ or by reasoning. (h) 36 × (28 – 16) 35 × (27 – 15) Evaluating individually 36 × (28 – 16) = 36 × 12 35 × (27 – 15) = 35 × 12 Since 36 > 35 Thus, LHS > RHS Answer: >