Question

Which of the following is a solution of 4x2 = − 9x − 4? (2 points) 9 plus or minus the square root of 17 divided by 8. negative 9 plus or minus the square root of 145 divided by 8. 9 plus or minus the square root of 145 divided by 8. negative 9 plus or minus the square root of 17 divided by 8.

Answer 1

Answer:

4x^2 + 9x + 4 = 0

Using the quadratic formula:

x = [-9 +- sqrt(81 - (-64)] / 2 * 4

x = [-9 +- sqrt (145)] / 8

So, the solution is your second answer:

negative 9 plus or minus the square root of 145 divided by 8.

Answer 2

Answer:

Negative 9 plus or minus the square root of 17 divided by 8.

Step-by-step explanation:

Which of the following is a solution of  4x² = − 9x − 4?

We are going to use formula method, to solve this quadratic equation

But first, we are going to rearrange the equation to make it in standard form;

4x²  =  -9x -4

Add 9x to both-side of the equation;

4x² + 9x = -9x + 4 + 9x

4x²  + 9x  = 4

subtract 4 from both-side of the equation;

4x²  + 9x -4 = 4-4

4x²  + 9x  - 4  = 0  --------------------(1)

So now, we can start solving

ax² + bx + c = 0 ----------------------(2)

Comparing equation(1) with equation (2)

a = 4        b =   9      and      c=   -4

Using the formula;

x = -b ±$\sqrt{b^{2} - 4ac }$  /   2a

We can substitute our values into the above formula;

x = -9 ± $\sqrt{9^{2} - 4.4.4 }$  /   2.4

x = -9 ± $\sqrt{81 - 64}$  /    8

x = -9 ± $\sqrt{17}$   /    8

Therefore the solution to this equation is; negative nine plus or minus the square root of 17 divided by 8