Question

8x? + 7x = -1Round your answer to the nearest hundredth.If there is more than one solution, separate them with commas.

Answer 1

Step-by-step explanation:

The general expression of a quadratic equation is;

`ax^2+bx+c=0`

Given the quadratic expression

`8x^2+7x=-1`

Firstly, we need to re-arrange and equate the expression to zero.

`8x^2+7x+1=0`

To factorize this expression, we will use the general formula:

`x=\frac{-b\pm\sqrt[]{b^2-4ac}}{2a}`

From the expression given, we can see that a = 8, b = 7 and c = 1

Substitute these values into the general formula as shown:

`\begin{gathered} x=\frac{-7\pm\sqrt[]{7^2-4(8)(1)}}{2(8)} \\ x=\frac{-7\pm\sqrt[]{49-32}}{16} \\ x=\frac{-7\pm\sqrt[]{17}}{16} \\ x=(-7\pm4.123)/(16) \end{gathered}`

Get the required values of x:

`\begin{gathered} x=(-7+4.123)/(16)\text{ and }(-7-4.123)/(16) \\ x=(-2.877)/(16)\text{and }(-11.123)/(16) \\ x\approx-0.18\text{ and -}0.70 \end{gathered}`

This shows that the solution to the quadratic equation is (-0.18, -0.70)