Question

Which are the solutions of x2 = -5x + 8?

-5 - 757 -5 + 157
-5717. -5
5-157.5+X57
5-x7.5407

Answer 1

`x= (-5+√(57) )/(2)`

or,
`x= (-5-√(57) )/(2)`

Explanation:

We are given a quadratic equation of single variable x which is
`x^(2) =-5x+8`.

Now, we can write
`x^(2) +5x-8 =0` ...... (1)

We can not solve the equation by factorizing the left hand term.

Therefore, use Sridhar Acharya Formula to get the solution

The formula gives if
`ax^(2) +bx+c =0`, then we can write

`x= \frac{-b+ \sqrt{b^(2)-4 * a * c } }{2a}`

or
`x= \frac{-b- \sqrt{b^(2)-4 * a * c } }{2a}`

Therefore, for this case

`x=\frac{-5+\sqrt{5^(2)-4 * 1 * (-8) } }{2}`

or,
`x=\frac{-5-\sqrt{5^(2)-4 * 1 * (-8) } }{2}`

⇒
`x= (-5+√(57) )/(2)`

or,
`x= (-5-√(57) )/(2)` (Answer)