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If α and β are the roots of the equation x2+5x+6=0, then the value of  αβ - (1α\frac1αα1​ + 1β\frac1ββ1​​) is:
Question

If α and β are the roots of the equation x2+5x+6=0, then the value of  αβ - (1α\frac1α1β\frac1β​) is:

A.

316\frac{-31}6​​

B.

316\frac{31}6​​

C.

416\frac{41}6​​

D.

416\frac{-41}6​​

Correct option is C

Given:

The quadratic equation is x2+5x+6=0
Roots are α and β
We need to find the value of αβ - (1α\frac1\alpha​+1β\frac1β​)

Formula Used:

For equation ax2+bx+c=0ax^2 +bx+c = 0  

Sum of roots = ba\frac{-b}{a} 

Product of roots = ca\frac{c}{a}​​

Solution: 

x2+5x+6=0 

Now, 

α+β = -ba\frac{b}a = -51\frac51 = -5

αβ = ca\frac{c}a = 61\frac61 = 6 

So, 

αβ − (1α\frac1α​+1β\frac1β

= αβ − α+βαβ\frac{α+β}{αβ} 

= 6 - 56\frac{-5}6 

= 6 + 56\frac56​ 

36+56\frac{36+5}6 

= 416\frac{41}6​​

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