Question

Solve the quadratic equation 3x - 5x - 7 = 0
Give your answers to 3 significant figures.

Answer 1

The solutions of
`3\cdot x^(2)-5\cdot x -7 = 0` are
`x_(1) \approx 2.573` and
`x_(2) \approx -0.907`.

Explanation:

The statement is incomplete. The complete description will be shown below:

Solve the quadratic equation
`3\cdot x^(2)-5\cdot x -7 = 0`. Give your answers to 3 significant figures.

From Algebra we know that second order polynomials of the form
`a\cdot x^(2)+b\cdot x + c = 0`,
`a \\e0` can be solved anatically by means of the Quadratic Formula, that is:

`x = \frac{-b\pm\sqrt{b^(2)-4\cdot a\cdot c}}{2\cdot a}` (1)

Where
`a`,
`b`,
`c` are coefficients of the given polynomial.

If we know that
`a = 3`,
`b = -5` and
`c = -7`, then the roots of the polynomial are:

`x_(1,2) = \frac{5\pm \sqrt{(-5)^(2)-4\cdot (3)\cdot (-7)}}{2\cdot (3)}`

`x_(1,2) = (5)/(6)\pm (√(109))/(6)`

That is,

`x_(1) \approx 2.573` and
`x_(2) \approx -0.907`

The solutions of
`3\cdot x^(2)-5\cdot x -7 = 0` are
`x_(1) \approx 2.573` and
`x_(2) \approx -0.907`.