Question

If a and b are the zeroes of the polyinomial x2 + 7x + 12, then the value of 1/a +1/b - 2ab is

Answer 1

$\bold{x^2 +7x +12}$

$\bold{x^2 +4x+3x +12}$

$\bold{x(x+4) +3(x+4)}$

$\bold{(x+3)(x+4)}$

$\bold{x = -3 \: \& \: x= -4}$

$let a= -3 & b = -4$

ATQ

$\bold{ \frac{1}{a} + \frac{1}{b} + 2ab}$

$\bold{( \frac{1}{ - 3}) + ( \frac{1}{ - 4} ) + 2( - 3)( - 4)}$

$\bold{\frac{ - 1}{3} - \frac{1}{4} + 24}$

$\bold{ \frac{281}{12} }$