Subject
Bank Exam
Topic
SBAC Bank Ltd. MTO 2014
If (x+2y)=a and (x-2y)=b, which of the following expression is equal to xy?
If (x+2y)=a and (x-2y)=b, which of the following expression is equal to xy?
ক)
abখ)
(a+b)/2গ)
(a2-b2)/8ঘ)
(a2-b2)/4Explanation
x+2y = a x-2y = b Adding above two eauations, x = a+b/2 Subtracting above two equations, y = a-b/4 so, xy = (a+b)/2 + (a-b)/4 = (a+b) (a-b)/8 = (a2 - b2)/8Related questions
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