Q13 of 52 Page 1

Find the value of m for which the roots of the equation mx(6x + 10) + 25 = 0, are equal.

mx (6x + 10) + 25 = 0


6mx2 + 10mx + 25 = 0


a = 6m


b = 10 m


c = 25


D = 0 (Roots are equal)


b2 – 4ac = 0


∴ (10m)2 – 6(6 m)(25) = 0


100 m2 – 600 m = 0


100 m(m – 6) = 0


100 m = 0 or m – 6 = 0


m = 0 or m = 6


As coefficient of x2 cannot be zero so Rejecting m = 0,


We get,


∴ m = 6


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