Question

LOAD OF QUESTIONS:

15 POINTS PER QUESTION.

5. Find the roots of the parabola given by the following equation. 2x2+ 5x - 9 = 2x.
(JUSTIFY)

Answer 1

x1=1,5

x2=-3

(2x-3)(x+3)=0

Explanation:

First we have to leave the equation of the parabola equalized ro 0:

`2x^2+ 5x - 9 = 2x.\\2x^2+5x-2x-9=0\\2x^2+3x-9=0`

We know have to search for two pairs of numbers the first one that multiplied give as result 2 and the second one has to be -9, then with a cross multiplication they will have to give as a resutl +5:

Pairs to +2:

2*1

1*2

Pairs to -9:

-3*3

3*-3

9*-1

-9*1

We will use 2*1 and -3*3:

(2x-3)(x+3)=0

SO that would be the answer for the roots of the parabola:

2x-3=0

x=3/2

x+3=0

x=-3

Answer 2

x=3/2,-3

x=1.5-3

x=1 1/2.-3