Question

please do in factorise..........at. following

Answer 1

(l+m)^2-4lm

; l^2+m^2+2lm-4lm

; l^2+m^2-2ml

;(l-m)^2

is your answer

Answer 2

${(l + m) }^{2} - 4lm \\ = {l}^{2} + {m}^{2} + 2ml - 4ml \\ = {l}^{2} + {m}^{2} - 2ml$