Factorise: (l+m)2 - (l-m)2
Answers
Answered by
354
Using the identity: a² - b² = (a+b)(a-b)
(l+m)² - (l-m)²
= [(l+m)+(l-m)]×[(l+m)-(l-m)]
= [l+m+l-m]×[l+m-l+m]
= [2l]×[2m]
=4lm
(l+m)² - (l-m)²
= [(l+m)+(l-m)]×[(l+m)-(l-m)]
= [l+m+l-m]×[l+m-l+m]
= [2l]×[2m]
=4lm
Answered by
77
Answer:
(l+m)²-(l-m)² = 4lm
Step-by-step explanation:
Given ,
(l+m)²-(l-m)²
= [(l+m)+(l-m)][(l+m)-(l-m))]
/* By algebraic identity:
a²-b² = (a+b)(a-b)*/
=(l+m+l-m)(l+m-l+m)
=2l × 2m
= 4lm
Therefore,
(l+m)²-(l-m)² = 4lm
•••♪
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