Ex 12.2, 3 - Subtract: (i) -5y^2 from y^2 (ii) 6xy from -12xy

 

  1. Chapter 12 Class 7 Algebraic Expressions
  2. Serial order wise

Transcript

Ex 12.2, 3 Subtract: (i) –5y2 from y2 y2 − (−5y2) = y2 + 5y2 = y2 (1 + 5) = y2 (6) = 6y2 Ex 12.2, 3 (Method 1) Subtract: (viii) 4pq – 5q2 – 3p2 from 5p2 + 3q2 – pq (5p2 + 3q2 – pq) − (4pq – 5q2 – 3p2) = 5p2 + 3q2 – pq − 4pq + 5q2 + 3p2 = 5p2 + 3p2 + 3q2 + 5q2 – pq − 4pq = p2 (5 + 3) + q2 (3 + 5) + pq (−1 − 4) = p2 (8) + q2 (8) + pq (−5) = 8p2 + 8q2 − 5pq

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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.