Question

I need to determine the correct set up for soloing this equation using the quadratic formula.

Answer 1

Hello !

Answer:

`\large \boxed{\sf Option\ C\to x=(-(-3)\pm√((-3)^2-4(4)(-9)))/(2(4)) }`

Explanation:

We want to find the value of x that satifies the following equation :

`\sf4x^2-5=3x+4`

Let's substract 3x+4 from both sides :

`\sf 4x^2-5-(3x+4)=3x+4-(3x+4)\\4x^2-5-3x-4=0\\\\4x^2-3x-9=0`

This equation is a quadratic equation in the form ax²+bx+c=0

The solution of this equation is given by the quadratic formula :

`\sf (-b\pm√(b^2-4ac))/(2a)`

In our equation, we have :

• a = 4
• b = -3
• c = -9

Let's substitute a, b and c with their values in the quadratic formula :

`\boxed{\sf x=((-3)\pm√((-3)^2-4(4)(-9)))/(2(4)) }`

Have a nice day ;)