Question

One x-intercept for a parabola is at the point

(0.2,0). Use the quadratic formula to find the
other x-intercept for the parabola defined by
this equation:
y = 5x² + 4x - 1
Separate the values with a comma. Round, if
necessary, to the nearest hundredth.

Answer 1

x=-1 or (-1,0)

Explanation:

(-4 +- sqrt(4^2-4(5)(-1)))/2*5

(-4 +- sqrt(16+20))/10

(-4 +- sqrt(36))/10

(-4 +- 6)/10

x= (-4+6)/10 = 2/10 = 1/5 = 0.2

x= (-4-6)/10 = -10/10 = -1

x-intercepts: (0.2,0), (-1,0)