Q6 of 55 Page 1

Solve for x: 36x2 – 12ax + (a2 – b2) = 0

Here, on comparing with general equation ax2 + bx + c = 0, we get

a = 36


b = - 12a


c = a 2 – b2


Now, Discriminant = D = (b2 – 4ac)


∴ D = [144a 2 - 4 × (36 × (a 2 - b2))]


= [144a 2 - 144a 2 + 144b2))]


= 144b 2


Therefore roots of the equation are given by:


x = (-b √D)/2a


∴ x = (12a (12b))/72


= (a + b)/6 or (a – b)/6


Thus the roots of the equation are: (a + b)/6 and (a – b)/6.


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