Identity 1 (Multilpying two brackets)

Transcript

Identity 1 (Multilpying two brackets)Our Identity 1 is Let’s check how we get it (𝒂+𝒎)(𝒃+𝒏)=𝑎 (𝑏+𝑛)+𝑚(𝑏+𝑛) =𝑎𝑏+𝑎𝑛+𝑚𝑏+𝑚𝑛 =𝒂𝒃+𝒎𝒃+𝒂𝒏+𝒎𝒏 Let’s do some examples Find (𝒂+𝟏)(𝒃−𝟏) (𝒂+𝟏)(𝒃−𝟏)=𝑎 (𝑏−1)+1(𝑏−1) =𝑎𝑏+𝑎 × (−1)+1 × 𝑏+1 × (−1) =𝒂𝒃−𝒂+𝒃−𝟏 Let’s do another Find (𝒂−𝟏)(𝒃+𝟏) (𝒂−𝟏)(𝒃+𝟏)=𝑎 (𝑏+1)−1(𝑏+1) =𝑎𝑏+𝑎 × 1+(−1)× 𝑏+(−1) × 1 =𝒂𝒃+𝒂−𝒃−𝟏