Question

If alpha and beta are zeros of a polynomial x²-5x+6 then find the value of alpha+beta - 3 alpha beta

Answer 1

p(x) =
${x}^{2} - 5x + 6$
$= > {x}^{2} - 2x - 3x + 6$
$x(x - 2) - 3(x - 2)$
$= > (x - 2)(x - 3)$
$so \: x = 2or3 \\ \alpha = 2 \\ \beta = 3$
$\alpha + \beta - 3 \alpha \beta = 2 + 3 - 3(2 \times 3)$
$= 5 - 18 = - 13$

Answer 2

Answer:

Step-by-step explanation:

p(x)= x^2-5x+6

Let α , β are its two zeroes

Then ,

α+β = -b/a i.e.. -(-5)/1 = 5

αβ = c/a i.e.. 6/1 = 6

Now ATQ,

α+β-3αβ = 5 - 3(6)

= 5 - 18

= -13