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

.(1 point)

1 answer

To solve the quadratic equation \(\frac{(x+16)^2}{9} = 7\), we will first isolate the squared term by multiplying both sides by 9:

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

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

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

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

Now, simplify \(\sqrt{63}\):

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

So we have:

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

Now, we can solve for \(x\) in both cases:

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

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

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

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

Next, we will calculate the approximate values of \(3\sqrt{7}\) and \(-3\sqrt{7}\) to find the values of \(x\).

First, let's calculate \(3\sqrt{7}\):

\[ \sqrt{7} \approx 2.6457513110645906 \quad \Rightarrow \quad 3\sqrt{7} \approx 3 \times 2.6457513110645906 \approx 7.9372539331 \]

So,

\[ x \approx 7.9372539331 - 16 \approx -8.0627460669 \quad \Rightarrow \quad x \approx -8.06 \quad (\text{rounded to the nearest hundredth}) \]

Now for the second case:

\[ -3\sqrt{7} \approx -7.9372539331 \quad \Rightarrow \quad x \approx -7.9372539331 - 16 \approx -23.9372539331 \quad \Rightarrow \quad x \approx -23.94 \quad (\text{rounded to the nearest hundredth}) \]

Thus, the two solutions for the equation \(\frac{(x+16)^2}{9} = 7\) are:

\[ \boxed{-8.06} \quad \text{and} \quad \boxed{-23.94} \]