1. ## finding the x

hi can someone help me verifty if this is right? is there a way to put the squared sign in here?

2xsquared - 4x - 5 = 0

2. Thats wrong

x=2.87 or -0.87

3. Originally Posted by likewhoa
hi can someone help me verifty if this is right? is there a way to put the squared sign in here?

2xsquared - 4x - 5 = 0

I've got a different solution.

I assume that you used the quadratic formula to solve the equation(?). If so you have:

$x = \dfrac{4 \pm \sqrt{16-4 \cdot 2 \cdot (-5)}}{2 \cdot 2}$

Now simplify.
Spoiler:
You should now have $x = 1\pm\frac12 \sqrt{14}$

4. Im using the quadratic formula

5. so you dont combine everything inside the radical then divide?

6. Originally Posted by likewhoa
so you dont combine everything inside the radical then divide?
Originally Posted by earboth
you have:

$x = \dfrac{4 \pm \sqrt{16-4 \cdot 2 \cdot (-5)}}{2 \cdot 2}$

...
It is now plain arithmetic:

$x = \dfrac{4 \pm \sqrt{16+40}}{2 \cdot 2}$

$x = \dfrac{4 \pm \sqrt{56}}{4}$

$x = \dfrac{4 \pm 2 \cdot \sqrt{14}}{4}$

$x = 1 \pm \frac12 \cdot \sqrt{14}$

7. ahhh okok thx

8. Originally Posted by likewhoa
hi can someone help me verifty if this is right? is there a way to put the squared sign in here?

2xsquared - 4x - 5 = 0

$2x^2-4x-5=0$