Question

alpha and beta are zeros. of x2-7x-18 what is alpha + beta?​

Answer 1

Given :-

α and β are the zeroes of x² - 7x - 18

To Find :-

Value of α + β

Solution :-

x² - 7x - 18 = 0

x² - (9x - 2x) - 18 = 0

x² - 9x + 2x - 18 = 0

x(x - 9) + 2(x - 9) = 0

(x - 9)(x + 2) = 0

Either

x - 9 = 0

x = 9

Or,

x + 2 = 0

x = -2

Let α = 9 and β = -2

α + β

9 + (-2)

9 - 2

7