One root of the quadratic equation x2 - 12x + a = 0, is thrice the other.

One root of the quadratic equation x2 - 12x + a = 0, is thrice the other. Find the value of a?

Quiz

Answer/Solution

27

Steps/Work

Let the roots of the quadratic equation be x and 3x.
Sum of roots = -(-12) = 12
a + 3a = 4a = 12 => a = 3
Product of the roots = 3a2 = 3(3)2 = 27.
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