Question

For the equation y = 2x2 − 5x + 18, choose the correct application of the quadratic formula.

x equals negative five plus or minus the square root of negative five squared minus four times two times eighteen, all divided by two times two

x equals five plus or minus the square root of negative five squared minus four times two times eighteen, all divided by two times two

x equals negative two plus or minus the square root of two squared minus four times negative five times eighteen, all divided by two times negative five

x equals two plus or minus the square root of two squared minus four times negative five times eighteen, all divided by two times negative five

Answer 1

x equals five plus or minus the square root of negative five squared minus four times two times eighteen, all divided by two times two

Answer 2

Option 2nd is correct

x equals five plus or minus the square root of negative five squared minus four times two times eighteen, all divided by two times two

Explanation:

Given the equation:

`y = 2x^2-5x+18`

Use the quadratic formula:

A quadratic equation
`y = ax^2+bx+c`.............[1], then the solution is given by:

`x = (-b \pm √(b^2-4ac))/(2a)`

On comparing given equation with [1]

a = 2 , b = -5 and c = 18

then;

`x = (-(-5) \pm √((-5)^2-4(2)(18)))/(2(2))`

⇒
`x = (5 \pm √((-5)^2-4(2)(18)))/(2(2))`

Therefore, the correct application of the quadratic formula is,

x equals five plus or minus the square root of negative five squared minus four times two times eighteen, all divided by two times two