Question

Find the zeroes of the following quadratic polynomial $6x^2+x-5$.

• A. 6, 5
• B. 2, 1
• C. $\frac{5}{6},-1$
• D. $\frac{1}{2},1$

Answer 1

The correct option is C

$\frac{5}{6},-1$

$6x^2+x-5=0$

We need to find two numbers 'a' and 'b' such that
$a\pm b=1,a\times b=-30$
$6-5=1,-5\times 6=-30$

$\Rightarrow 6x^2+6x-5x-5=0$
$\Rightarrow 6x(x+1)-5(x+1)=0$
$\Rightarrow (6x-5)(x+1)=0$
$\Rightarrow x=\frac{5}{6}orx=-1$

Thus, the zeroes of the polynomial
$6x^2+x-5$ are $\frac{5}{6}$ and -1.