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Let the roots of the equation ax²+bx+c = 0 be 3k and 4k (where k is some constant).
By Vieta's formulas, we know that the sum of the roots of a quadratic equation is equal to -b/a and the product of the roots is equal to c/a.
Thus, we have:
3k + 4k = -b/a
7k = -b/a
k = -b/7a
3k * 4k = c/a
12k² = c/a
12(-b/7a)² = c/a
12b²/49a² = c/a
Multiplying both sides by 49a², we get:
12b² = 49ac
Therefore, we have shown that if the roots of the quadratic equation ax²+bx+c = 0 are in the ratio of 3:4, then 12b² = 49ac.
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