(a + b − c + d)2 - (a − b + c − d)2 = ?
Answer & explanation
Correct answer: option 1
Given,
(a + b – c + d)2 – (a – b + c – d)2
Put a = 1, b = 2, c = 3 and d = 4 and satisfy from the options,
= (1 + 2 – 3 + 4)2 – (1 – 2 + 3 – 4)2
= 16 – 4 = 12
If we check option 2 =
4a (b + d – c)
= 4 × 1 (2 + 4 – 3)
= 4 × 3
= 12 (satisfied)
So the answer is = 4a (b + d – c)