Each of the following cubic equations has roots , , . Find, for each case, +

Each of the following cubic equations has roots α, β, γ. Find, for each case, α + β + γ and αβγ.

a. x³ + 3x² – 5 = 0

b. 2x³ + 5x² - 6 = 0

c. x³ + 7x – 9 = 0