Question

Solve for x in the expression using the quadratic formula. 2x2+31x−4.9=0

Answer 1

Answer:

$x=\frac{-31\pm \sqrt{1000.2}}{4}$

Step-by-step explanation:

Given quadratic equation,

$2x^2+31x-4.9=0$

Since, by the quadratic formula,

The solution of a quadratic equation $ax^2+bx+c=0$ is,

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

Here, a = 2, b = 31, c = -4.9,

Thus, by the quadratic formula,

$x=\frac{-31\pm \sqrt{31^2-4\times 2\times -4.9}}{2\times 2}$

$=\frac{-31\pm \sqrt{961+39.2}}{4}$

$=\frac{-31\pm \sqrt{1000.2}}{4}$

$\implies x = \frac{-31+\sqrt{1000.2}}{4}\text{ or }x=\frac{-31- \sqrt{1000.2}}{4}$