Question

Which equation has the solutions x = StartFraction 5 plus-or-minus 2 StartRoot 7 EndRoot Over 3 EndFraction? 3x2 – 5x + 7 = 0 3x2 – 5x – 1 = 0 3x2 – 10x + 6 = 0 3x2 – 10x – 1 = 0

Answer 1

Answer:

$3x^2-10x - 1$

Step-by-step explanation:

Since,

By the quadratic formula the solution of the equation ax² + bx + c = 0,

$x =\frac{-b\pm\sqrt{b^2 - 4ac}}{2a}$

Using the formula,

The solution of the equation $3x^2 -5x + 7 =0$

$x=\frac{5\pm \sqrt{25-84}}{6}=\frac{5\pm \sqrt{-59}}{6}=\frac{5\pm i\sqrt{59}}{6}$

The solution of the equation $3x^2 -5x - 1 =0$

$x=\frac{5\pm \sqrt{25+12}}{6}=\frac{5\pm \sqrt{37}}{6}$

The solution of the equation $3x^2 -10x + 6 =0$

$x=\frac{-10\pm \sqrt{100-72}}{6}=\frac{5\pm \sqrt{36}}{6}=\frac{5\pm 6}{6}$

The solution of the equation $3x^2 -10x - 1 =0$

$x=\frac{10\pm \sqrt{100+12}}{6}=\frac{10\pm \sqrt{112}}{6}=\frac{10\pm 4\sqrt{7}}{6}=\frac{5\pm 2\sqrt{7}}{3}$

Hence, LAST option is correct.

Learn more :

Find quadratic function by its roots,

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Answer 2

Answer:

D.

Step-by-step explanation:

Edge brudha