+498 The function f(x) is defined for 1 \le x \le 5 as follows:
f(x) = 2x + 8 if 1 \le x \le 2
f(x) = 13 - 5x if 2 < x \le 3
f(x) = 20 - 14x if 3 < x \le 4
f(x) = 40 + 5x if 4 < x \le 5
Find all real numbers x such that f(x) = x. If you find more than one answer, list them all, separated by commas.
+67 Ok, we can go one by one to solve these problems.
However, let's note that if we have f(x) = x, we set the function's right side to equal x.
Then, we see if the x value satisfies the conditions given.
First, we have \(f(x)=2x+8\). Setting this to equal x, we find that \(x=2x+8\)
Solving for x, we find that \(x=-8\). This doesn't satisfy the condition \(1 \le x\le 2\), so it is not a valid solution.
Next, we have \(f(x)=13-5x\). Setting this to equal x, we have \(x=13-5x\)
Finding the value of x, we get \(x=13/6\). This satisfies the interval, so it is a solution.
Third, we have \(f(x)=20-14x\). Since this equals x, we can write \(x=20-14x\)
Trying to find x, we have that \(x=4/3\). This does NOT satisfy the interval, so it is not a solution.
Lastly, we have \(f(x)=40+5x\). setting this function to equal x, we have \(x=40+5x\)
Solving for x, we get \(x=-10\), which is invalid.
Thus, the only value that works is 13/6.
So our answer is 13/6.
Thanks! 
Credits to notthatsmart
