Question

Which are the solutions of x2 = -5x + 8?
-5 - 757 -5 + 157
-5717. -5
5-157.5+X57
5-x7.5407

Answer 1

Answer:

$x= \frac{-5+\sqrt{57} }{2}$

or, $x= \frac{-5-\sqrt{57} }{2}$

Step-by-step 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

$x= \frac{-b+ \sqrt{b^{2}-4 \times a \times c } }{2a}$

or $x= \frac{-b- \sqrt{b^{2}-4 \times a \times c } }{2a}$

Therefore, for this case

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

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

⇒ $x= \frac{-5+\sqrt{57} }{2}$

or, $x= \frac{-5-\sqrt{57} }{2}$ (Answer)