Find the zeroes of the quadratic polynomial 5x² + 8x -4 and verify the relationship between zeroes and coefficient of the polynomial

Let f(x) = 5x² + 8x - 4 and α and β be its zeroes

Here a = 5, b = 8 and c = -4

5x² + 8x - 4 = 0

5x² + 10x - 2x - 4 = 0

5x(x + 2) - 2(x + 2) = 0

(x + 2)(5x - 2) = 0

x + 2 = 0 or 5x - 2 = 0

x = -2 or x= 2/5

So, the zeroes are α = -2 and β = 2/5

α + β = -2 + 2/5 = -8/5

-b/a = -8/5

So, α + β = -b/a

αβ = -2*2/5 = -4/5

c/a = -4/5

So, αβ = c/a