# Ex 12.3, 4 - Chapter 12 Class 7 Algebraic Expressions

Last updated at Dec. 21, 2018 by Teachoo

Last updated at Dec. 21, 2018 by Teachoo

Transcript

Ex 12.3, 4 If a = 2, b = – 2, find the value of: (i) a2 + b2 a2 + b2 Putting a = 2, b = −2 = (2)2 + (−2)2 = 4 + 4 = 8 Ex 12.3, 4 If a = 2, b = – 2, find the value of: (ii) a2 + ab + b2 a2 + ab + b2 Putting a = 2, b = −2 = (2)2 + (2)(−2) + (−2)2 = 4 − 4 + 4 = 0 + 4 = 4 Ex 12.3, 4 If a = 2, b = – 2, find the value of: (iii) a2 – b2 a2 – b2 Putting a = 2, b = −2, = (2)2 − (−2)2 = 4 − 4 = 0

Ex 12.3

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