Which of the following is a solution to the quadratic equation 4x2+2x=10

? Assume that the solution has been rounded to the nearest hundredth, if applicable.(1 point)
Responses

x=−0.77
x equals negative 0.77

x=−1.85
x equals negative 1.85

x=1.04
x equals 1.04

x=1.15

1 answer

To solve the quadratic equation \(4x^2 + 2x = 10\), we first rearrange it into standard form:

\[ 4x^2 + 2x - 10 = 0 \]

Next, we can use the quadratic formula:

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

where \(a = 4\), \(b = 2\), and \(c = -10\).

Now we calculate the discriminant (\(b^2 - 4ac\)):

\[ b^2 - 4ac = 2^2 - 4 \cdot 4 \cdot (-10) = 4 + 160 = 164 \]

Now substitute the values into the quadratic formula:

\[ x = \frac{-2 \pm \sqrt{164}}{2 \cdot 4} \]

Calculating \(\sqrt{164}\):

\[ \sqrt{164} \approx 12.81 \]

So we find:

\[ x = \frac{-2 \pm 12.81}{8} \]

Calculating the two possible values for \(x\):

  1. \(x = \frac{-2 + 12.81}{8} = \frac{10.81}{8} \approx 1.35\)
  2. \(x = \frac{-2 - 12.81}{8} = \frac{-14.81}{8} \approx -1.85\)

Thus, the approximate solutions to the equation rounded to the nearest hundredth are:

\[ x \approx 1.35 \quad \text{and} \quad x \approx -1.85 \]

From the given options, the solution \(x = -1.85\) is the correct one.