Verify Answer on Quadratic Formula

[Guest]

x^2 - 2x = 15x - 10

x^2 - 2x - 15x +10 = 0

x^2 - 17x + 10 =0 a= 1 , b = -17 , c= 10

x = - b +/- SQRT b^2 - 4ac / 2a

x = - (-17) +/- SQRT -17^2 - 4(1)(10) / 2(1)

x = 17 +/- SQRT 289 - 40 / 2

x = 17 +/- SQRT 249 / 2

 

[daon]

These "checks" aren't an occasion for a new thread. This is easy to check for yourself.

$\displaystyle x^2 - 2x = 15x - 10$

Take one of your x values, and replace every x you see with that x value.

So, lets take $\displaystyle x = \frac{17 + \sqrt{249}}{2}$.

$\displaystyle ( \frac{17 + \sqrt{249}}{2})^2 - 2( \frac{17 + \sqrt{249}}{2}) = 15( \frac{17 + \sqrt{249}}{2}) - 10$

Now, its your job to verify that the left-hand side is equal to the right-hand side.

-Daon