Question

please solve this question with explaination please (class 10 maths chapter 2)​

Answer 1

$\alpha - \beta = 1 \\ also \\ \alpha + \beta = - \frac{b}{a} = 5$

on adding both, we get

$2 \alpha = 6 \\ \alpha =3 \\ and \: \beta = 2$

so,

$\alpha \beta = 6 = \frac{c}{a}$

hence k = 6

Answer 2

Pre - required knowledge :

• α + β = - Coefficient of x/Coefficient of x²

• αβ = Constant Term/Coefficient of x²

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Solution : In polynomial x² - 5x + k,

→ α + β = 5

Given : α - β = 1

On adding both equations we get,

→ α = 3

By substituting values we get,

→ 3 + β = 5

→ β = 2

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Since αβ = k

→ 3 × 2 = 6 = k

Hence value of k is 6.