# Ex 12.3, 2 - 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, 2 If p = – 2, find the value of: (i) 4p + 7 4p + 7 Putting p = −2 = 4 (−2) + 7 = − 8 + 7 = −1 Ex 12.3, 2 If p = – 2, find the value of: (ii) – 3p2 + 4p + 7 – 3p2 + 4p + 7 Putting p = − 2 = −3 (−2)2 + 4 (−2) + 7 = −3 (4)2 − 8 + 7 = −3 × 4 − 8 + 7 = –12 – 1 = −13 Ex 12.3, 2 If p = – 2, find the value of: (iii) – 2p3 – 3p2 + 4p + 7 – 2p3 – 3p2 + 4p + 7 Putting p = −2 = −2 (−2)3 − 3 (−2)2 + 4 (−2) + 7 = −2 (−8) − 3 (4) − 8 + 7= = 16 − 12 − 1 = 4 − 1 = 3

Ex 12.3

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