The zeros of the polynomial

Question:

The zeros of the polynomial $x^{2}+\frac{1}{6} x-2$ are

(a) $-3,4$

(b) $\frac{-3}{2}, \frac{4}{3}$

(c) $\frac{-4}{3}, \frac{3}{2}$

(d) none of these

 

Solution:

(b) $\frac{-3}{2}, \frac{4}{3}$

Let $f(x)=x^{2}+\frac{1}{6} x-2=0$

$=>6 x^{2}+x-12=0$

$=>6 x^{2}+9 x-8 x-12=0$

$=>3 x(2 x+3)-4(2 x+3)=0$

$=>(2 x+3)(3 x-4)=0$

$\therefore x=\frac{-3}{2}$ or $x=\frac{4}{3}$

 

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