Recognize repeating pattern: First, let's recognize that the expression is a repeating pattern, so we can set x to the entire expression. That means x=7+x.
Square both sides: Now, we square both sides to get rid of the square root. So, x2=7+x.
Rearrange equation: Next, we rearrange the equation to set it to zero. We get x2−x−7=0.
Use quadratic formula: We can't factor this easily, so we'll use the quadratic formula: x=2a−b±b2−4ac, where a=1, b=−1, and c=−7.
Plug values into formula: Plugging the values into the quadratic formula, we get x=21±1+4×7.
Simplify expression: Simplify the expression under the square root: x=21±1+28.
Add numbers under square root: Add the numbers under the square root: x=21±29.
Take positive square root: Since we're looking for a positive value of x (because we can't have a negative length), we take the positive square root: x=(1+29)/2.