Question 1 - Figure it out (Page 172) - Solving Equations - Chapter 7 Class 7 - Finding the Unknown (Ganita Prakash II)

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Question 1 - Figure it out (Page 172) Solve these equations and check the solutions. (a) 3x – 10 = 35Solving 3x – 10 = 35 Putting 10 on right side 3x = 35 + 10 3x = 45 x = 45/3 x = 15 Thus, x = 15 is the solution of the equation Checking solution 3x – 10 = 35 Putting x = 15 3 × 15 – 10 = 35 45 – 10 = 35 35 = 35 It is true Thus, the solution is correct Question 1 - Figure it out (Page 172) Solve these equations and check the solutions. (b) 5s = 3sSolving 5s = 3s Putting 3s on right side 5s – 3s = 0 2s = 0 s = 0/2 s = 0 Thus, s = 0 is the solution of the equation Checking solution 5s = 3s Putting s = 0 5 × 0 = 3 × 0 0 = 0 It is true Thus, the solution is correct Question 1 - Figure it out (Page 172) Solve these equations and check the solutions. (c) 3u – 7 = 2u + 3Solving 3u – 7 = 2u + 3 Putting 7 on right side 3u = 2u + 3 + 7 3u = 2u + (3 + 7) 3u = 2u + 10 Putting 2u on left side 3u – 2u = 10 u = 10 Thus, u = 10 is the solution of the equation Checking solution 3u – 7 = 2u + 3 Putting u = 10 3 × 10 – 7 = 2 × 10 + 3 30 – 7 = 20 + 3 23 = 23 It is true Thus, the solution is correct Question 1 - Figure it out (Page 172) Solve these equations and check the solutions. (d) 4 (m + 6) – 8 = 2m – 4Solving 4 (m + 6) – 8 = 2m – 4 4 × m + 4 × 6 – 8 = 2m – 4 4m + 24 – 8 = 2m – 4 4m + (24 – 8) = 2m – 4 4m + 16 = 2m – 4 Putting 16 on right side 4m = 2m – 4 – 16 4m = 2m – (4 + 16) 4m = 2m – 20 Putting 2m on left side 4m – 2m = –20 2m = –20 m = (−20)/2 m = –10 Thus, m = –10 is the solution of the equation Checking solution 4 (m + 6) – 8 = 2m – 4 Putting m = –10 4 (–10 + 6) – 8 = 2 × (–10) – 4 4 × (–4) – 8 = –20 – 4 –16 – 8 = – (20 + 4) – (16 + 8) = – (20 + 4) – 24 = – 24 It is true Thus, the solution is correct Question 1 - Figure it out (Page 172) Solve these equations and check the solutions. (e) 𝑢/15=6Solving 𝑢/15=6 Putting 15 on right side u = 6 × 15 u = 90 Thus, u = 90 is the solution of the equation Checking solution 𝑢/15=6 Putting u = 90 90/15=6 6 = 6 It is true Thus, the solution is correct