Question

2x2 − 1 = 3x + 4 Which equation correctly applies the quadratic formula?

Answer 1

The answer is
`x = - (- 3) +\sqrt{(- 3)^2 - 4(2)(-5)`

2(2)

Explanation:

Answer 2

Standard form: ax^2 + bx + c = y

Steps to simplify:

2x^2 - 1 = 3x + 4

~Subtract (3x + 4) to both sides

2x^2 - 1 - 3x + 4 = 3x + 4 - 3x + 4

~Simplify

2x^2 - 3x - 5 = 0

(a = 2, b = -3, c = -5)

Now that we know what these values are, we can use the quadratic formula to solve.

`x=(-b-+√(b^2-4ac) )/(2a) \\x = (-(-3)-+√(-3^2-4(2)(-5)) )/(2(2))\\x= (-3-+√(49) )/(4) \\x=(3-+7)/(4) \\x = (10)/(4)~or~(-4)/(4) \\x=(5)/(2)~or~-1`

Answer: x = 5/2 or x = -1

Best of Luck!