6. The dimensions of a polygon [tex]\(ABCD\)[/tex], shown below, are as follows:
[tex]\[
\begin{array}{l}
AB = 12, \ BC = \sqrt{2x + 54}, \\
CD = 10, \ \text{and} \ AD = 6.
\end{array}
\][/tex]

The perimeter of the polygon is 35.

What is the radical equation that must be solved to determine [tex]\(x\)[/tex]? Then, solve the equation for [tex]\(x\)[/tex].



Answer :

To solve the problem, we need to determine the value of [tex]\( x \)[/tex] given the perimeter of the polygon [tex]\( ABCD \)[/tex]. We know the lengths of sides [tex]\( AB \)[/tex], [tex]\(\ BC \)[/tex], [tex]\( CD \)[/tex], and [tex]\( AD \)[/tex], and we know the total perimeter.

1. List the given information:
[tex]\[ AB = 12, \quad BC = \sqrt{2x + 54}, \quad CD = 10, \quad AD = 6 \][/tex]

2. Calculate the perimeter:
The perimeter of polygon [tex]\( ABCD \)[/tex] is given as 35. Hence, we can set up the following equation:
[tex]\[ AB + BC + CD + AD = 35 \][/tex]

3. Substitute the given lengths into the perimeter equation:
[tex]\[ 12 + \sqrt{2x + 54} + 10 + 6 = 35 \][/tex]

4. Simplify the equation:
Combine the known lengths:
[tex]\[ 12 + 10 + 6 = 28 \][/tex]
Thus, the equation becomes:
[tex]\[ 28 + \sqrt{2x + 54} = 35 \][/tex]

5. Isolate the square root term:
Subtract 28 from both sides:
[tex]\[ \sqrt{2x + 54} = 35 - 28 \][/tex]
[tex]\[ \sqrt{2x + 54} = 7 \][/tex]

6. Square both sides to eliminate the square root:
[tex]\[ (\sqrt{2x + 54})^2 = 7^2 \][/tex]
[tex]\[ 2x + 54 = 49 \][/tex]

7. Solve for [tex]\( x \)[/tex]:
Subtract 54 from both sides:
[tex]\[ 2x = 49 - 54 \][/tex]
[tex]\[ 2x = -5 \][/tex]
Divide by 2:
[tex]\[ x = \frac{-5}{2} \][/tex]

Therefore, the radical equation to be solved is
[tex]\[ \sqrt{2x + 54} + 28 = 35 \][/tex]
and the solution to this equation is
[tex]\[ x = -\frac{5}{2} \][/tex]