Question

Solve y=-3x² + 4.5x – 20
Use the Quadratic formula

Answer 1

`x=0.75 \pm 2.47067i`

Explanation:

Quadratic Formula:
`x=(-b \pm √(b^2-4ac) )/(2a)`

√-1 is imaginary number i

Step 1: Define

y = -3x² + 4.5x - 20

a = -3

b = 4.5

c = -20

Step 2: Substitute and Evaluate

`x=(-4.5 \pm √(4.5^2-4(-3)(-20)) )/(2(-3))`

`x=(-4.5 \pm √(20.25-240) )/(-6)`

`x=(-4.5 \pm √(-219.75) )/(-6)`

`x=(-4.5 \pm √(219.75)(√(-1) ) )/(-6)`

`x=(-4.5 \pm i√(219.75) )/(-6)`

`x=(4.5 \pm i14.824 )/(6)`

`x=0.75 \pm 2.47067i`