Me resuelven estos dos problemas con la fórmula generala) 2x ^ 2 - 3x - 1b)3x ^ 2 - 2x - 5?

Soluciones :

Recordando la fórmula general de segundo grado :

<img src="https://tex.z-dn.net/?f=x%3D%5Cfrac%7B-b%5Cpm%5Csqrt%7Bb%5E%7B2%7D-4ac%7D%7D%7B2a%7D%5C%2C%5Ctextup%7Bluego%7D%5C%5C2x%5E%7B2%7D-3x-1%3D0%5C%5Ca%3D2%5C%5Cb%3D-3%5C%5Cc%3D-1" />

Resolviendo :

<img src="https://tex.z-dn.net/?f=x%3D%5Cfrac%7B3%5Cpm%5Csqrt%7B%28-3%29%5E%7B2%7D-4%282%29%28-1%29%7D%7D%7B2%282%29%7D%5C%5Cx%3D%5Cfrac%7B3%5Cpm%5Csqrt%7B9%2B8%7D%7D%7B4%7D%5C%5Cx%3D%5Cfrac%7B3%5Cpm%5Csqrt%7B17%7D%7D%7B4%7D%5C%5Cx_%7B1%7D%3D%5Cfrac%7B3%2B%5Csqrt%7B17%7D%7D%7B4%7D%5C%5Cx_%7B2%7D%3D%5Cfrac%7B3-%5Csqrt%7B17%7D%7D%7B4%7D" />

Para.

La segunda ecuación se tiene :

<img src="https://tex.z-dn.net/?f=3x%5E%7B2%7D-2x-5%3D0%5C%5Ca%3D3%5C%5Cb%3D-2%5C%5Cc%3D-5" />

Luego :

<img src="https://tex.z-dn.net/?f=x%3D%5Cfrac%7B2%5Cpm%5Csqrt%7B%28-2%29%5E%7B2%7D-4%283%29%28-5%29%7D%7D%7B2%283%29%7D%5C%5Cx%3D%5Cfrac%7B2%5Cpm%5Csqrt%7B4%2B60%7D%7D%7B6%7D%5C%5Cx%3D%5Cfrac%7B2%5Cpm%288%29%7D%7B6%7D%5C%5Cx_%7B1%7D%3D%5Cfrac%7B2%2B8%7D%7B6%7D%3D%5Cfrac%7B10%7D%7B6%7D%3D%5Cfrac%7B5%7D%7B3%7D%5C%5Cx_%7B2%7D%3D%5Cfrac%7B2-8%7D%7B6%7D%3D-1" />

Saludos.