Question 3 - Page 146 - Square of the Sum/Difference of Two Numbers - Chapter 6 Class 8 - We Distribute yet things Multiply (Ganita Prakash)

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Question 3 - Page 146 Expand (3j + 2k)2 using both the identity and by applying the distributive property.Using Identity - (𝒂+𝒃)^𝟐 (𝟑𝒋+𝟐𝒌)^𝟐=(3𝑗)^2 + 2 × 3𝑗 × 2𝑘+〖(2𝑘)〗^2 =3^2 × 𝑗^2 +2 × 3 × 2 × 𝑗𝑘 +2^2 × 𝑘^2 =𝟗𝒋^𝟐+𝟏𝟐𝒋𝒌+𝟒𝒌^𝟐 Using Distributive Property (𝟑𝒋+𝟐𝒌)^𝟐=(3𝑗+2𝑘) × (3𝑗+2𝑘) =3𝑗(3𝑗+2𝑘)+2𝑘(3𝑗+2𝑘) =3𝑗 × 3𝑗+3𝑗 × 2𝑘+2𝑘 × 3𝑗+2𝑘 × 2𝑘 =9𝑗^2+6𝑗𝑘+6𝑗𝑘+4𝑘^2 =𝟗𝒋^𝟐+𝟏𝟐𝒋𝒌+𝟒𝒌^𝟐