9514 1404 393
Answer:
-8
Step-by-step explanation:
If α and β are roots of x^2 +5x +a = 0, then we must have ...
(x -α)(x -β) = x^2 +5x +a
x^2 -(α+b)x +αβ = x^2 +5x +a
Then ...
α + β = -5
Together with the other relation between the roots, we have a system of equations in α and β.
Using the above to write an expression for β, we get ...
β = -α -5
Substituting this into the given relation, we have an equation for α:
2α +5(-α -5) = -1
-3α -25 = -1 . . . . . . eliminate parentheses
-24 = 3α . . . . . . . . add 3α +1
-8 = α
The root α is equal to -8.
