Solve the quadratic equation using square roots. Round to the nearest hundredth if necessary: (x+16)^2/9 = 7

1 answer

To solve the equation \(\frac{(x+16)^2}{9} = 7\), we start by eliminating the fraction. We can do this by multiplying both sides by 9:

\[ (x+16)^2 = 7 \times 9 \]

Calculating the right side gives:

\[ (x+16)^2 = 63 \]

Now, we will take the square root of both sides. Remember to consider both the positive and negative roots:

\[ x + 16 = \pm \sqrt{63} \]

Next, we can simplify \(\sqrt{63}\):

\[ \sqrt{63} = \sqrt{9 \times 7} = 3\sqrt{7} \]

Now we have two equations to solve:

  1. \(x + 16 = 3\sqrt{7}\)
  2. \(x + 16 = -3\sqrt{7}\)

For the first equation:

\[ x + 16 = 3\sqrt{7} \]

Subtracting 16 from both sides gives:

\[ x = 3\sqrt{7} - 16 \]

For the second equation:

\[ x + 16 = -3\sqrt{7} \]

Subtracting 16 from both sides gives:

\[ x = -3\sqrt{7} - 16 \]

Next, we will approximate the values by calculating \(\sqrt{7}\):

\[ \sqrt{7} \approx 2.64575 \]

Now we can find \(3\sqrt{7}\):

\[ 3\sqrt{7} \approx 3 \times 2.64575 \approx 7.93725 \]

Substituting this into the first equation:

\[ x \approx 7.93725 - 16 \approx -8.06275 \]

For the second equation:

\[ -3\sqrt{7} \approx -7.93725 \]

So,

\[ x \approx -7.93725 - 16 \approx -23.93725 \]

Rounding to the nearest hundredth, we have:

  1. \(x \approx -8.06\)
  2. \(x \approx -23.94\)

Thus, the solutions to the equation are:

\[ x \approx -8.06 \quad \text{and} \quad x \approx -23.94 \]