Question 8 (iv) - Algebra Identities and Formulas - Chapter 8 Class 8 Algebraic Expressions and Identities

Last updated at August 14, 2026 by

Ex 9.5, 8 - Chapter 9 Class 8 Algebraic Expressions and Identities - Part 4

Ex 9.5, 8 - Chapter 9 Class 8 Algebraic Expressions and Identities - Part 5

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Question 8 Using (𝑥+𝑎)(𝑥+𝑏)=𝑥^2+(𝑎+𝑏)𝑥+𝑎𝑏 , find (iv) 9.7 × 9.8 9.7 ×9.8 = (10−0.3)×(10−0.2) = (10+(−0.3))×[10+(−0.2)] (𝑥+𝑎)(𝑥+𝑏)=𝑥^2+(𝑎+𝑏)𝑥+𝑎𝑏 Putting 𝑥 = 10 , 𝑎 = −0.3 & 𝑏 = −0.2 = (10)^2+(−0.3−0.2)(10)+(−0.3)(−0.2) = 100+(−0.5×10)+(0.3×0.2) = 100−(5/10×10)+(3/10×2/10) = 100−5+6/100 = 95+0.06 = 𝟗𝟓.𝟎𝟔

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