`?^(2) + sqrt(400) = 6^(2)`

Options

A. 3
B. 4
C. 2
D. 1

Answer

To solve the equation \( ?^2 + \sqrt{400} = 6^2 \), we will follow these steps:

### Step 1: Simplify \(\sqrt{400}\) and \(6^2\)
First, we need to calculate the square root of 400 and the square of 6.

\[ \sqrt{400} = 20 \]
\[ 6^2 = 36 \]

### Step 2: Substitute the values into the equation
Now, we can substitute these values back into the original equation:

\[ ?^2 + 20 = 36 \]

### Step 3: Isolate \(?^2\)
Next, we need to isolate \(?^2\) by subtracting 20 from both sides of the equation:

\[ ?^2 = 36 - 20 \]

### Step 4: Calculate the right side
Now, we perform the subtraction:

\[ ?^2 = 16 \]

### Step 5: Solve for \(?\)
To find \(?\), we take the square root of both sides:

\[ ? = \sqrt{16} \]
\[ ? = 4 \]

Thus, the value of \(?\) is 4.

### Final Answer
The value of \(?\) is 4.

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