Question 1 - Page 140 - Distributive Property - Chapter 6 Class 8 - We Distribute yet things Multiply (Ganita Prakash)

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Question 1 - Page 140 Use Identity 1 to find how the product changes when (i) one number is decreased by 2 and the other increased by 3; (ii) both numbers are decreased, one by 3 and the other by 4. Our Identity 1 is (i) one number is decreased by 2 and the other increased by 3; So, we need to solve (𝒂−𝟐)(𝒃+𝟑) Now, (𝒂−𝟐)(𝒃+𝟑)=𝑎 (𝑏+3)−2(𝑏+3) =𝑎𝑏+𝑎 × 3+(−2)× 𝑏+(−2) × 3 (ii) both numbers are decreased, one by 3 and the other by 4. So, we need to solve (𝒂−𝟐)(𝒃+𝟑) So, we need to solve (𝒂−𝟐)(𝒃+𝟑) Now, (𝒂−𝟑)(𝒃−𝟒)=𝑎 (𝑏−4)−3(𝑏−4) =𝑎𝑏+𝑎 × (−4)+(−3)× 𝑏+(−3) × (−4) =𝒂𝒃−𝟒𝒂−𝟑𝒃+𝟏𝟐