Advertisements
Advertisements
Question
Simplify: (a + b)2 – (a – b)2
Sum
Advertisements
Solution
Applying the identities
(a + b)2 = a2 + 2ab + b2
(a – b)2 = a2 – 2ab + b2
(a + b)2 – (a – b)2 = a2 + 2ab + b2 – [a2 – 2ab + b2]
= a2 + 2ab + b2 – a2 + 2ab – b2
= a2(1 – 1) + ab(2 + 2) + b2(1 – 1)
= 0a2 + 4ab + 0b2 = 4ab
(a + b)2 – (a – b)2 = 4ab
shaalaa.com
Is there an error in this question or solution?
APPEARS IN
RELATED QUESTIONS
Expand (2)2p − 3q
Expand: (98)2
Expand (5p – 1)2
(a – 1)2 = a2 – 1
Factorise the following using suitable identity
x2 – 8x + 16
a2 – b2 is equal to ______.
Factorise the following, using the identity a2 – 2ab + b2 = (a – b)2.
y2 – 14y + 49
Factorise the following, using the identity a2 – 2ab + b2 = (a – b)2.
a2y3 – 2aby2 + b2y
If m – n = 16 and m2 + n2 = 400, then find mn.
Verify the following:
(a – b)(a – b)(a – b) = a3 – 3a2b + 3ab2 – b3
