Factorisation using identities
Last updated at Dec. 16, 2024 by Teachoo
Transcript
Ex 12.2, 1 Factorise the following expressions. (vii) 〖"(l + m)" 〗^2 – 4lm (Hint: Expand 〖"(l + m)" 〗^2 first)〖"(l + m)" 〗^2 – 4lm = 𝑙^2+𝑚^2+2𝑙𝑚 −4𝑙𝑚 = 𝑙^2+𝑚^2+𝑙𝑚 (2−4) = 𝒍^𝟐+𝒎^𝟐−𝟐𝒍𝒎 = (𝒍−𝒎)^𝟐 Using (𝒂+𝒃)^𝟐=𝑎^2+𝑏^2+2𝑎𝑏 Here, 𝑎 = l and b = m Using (𝒂−𝒃)^𝟐=𝑎^2+𝑏^2−2𝑎𝑏 Here, 𝑎 = l and b = m