Question

4 Consider the quadratic equation below.
`4 {x}^(2) - 5 = 3x + 4` Determine the correct set-up for solving the equation using the quadratic formula.

Answer 1

The equation:

4x² - 5 = 3x + 4

First, we need to re-arrange in the form : ax² + bx + c

4x² - 5 = 3x + 4

4x² - 3x -5 -4 = 0

4x² - 3x -9 =0

comparing the above with ax² + bx + c

a= 4 b= -3 c=-9

we will then substitute the values into the quadratic formula:

`x\text{ = }\frac{-b\pm\sqrt[]{b^2-4ac}}{2a}`
`x=\frac{-(-3)\pm\sqrt[]{(-3)^2-4(4)(-9)}}{2(4)}`