First, we know L and W are the same number. The in the end the Length is 6 more, therefore we add 6. The equations begins as so
2x+6=27
-6
2x=21
/2
x=10.5
+6
Therefore the Width =10.5 M
The Length = 16.5 M
The number in the parenthesis is the X value and they are looking for what the Y value is at that specific X.
So when you look at f(-2), find the Y value where the line crosses.
At X-2, the line crosses Y at -2
At X = 2, the line crosses at Y = 2
At X = 4, the line crosses at Y = 1
The answer is -2,2,1
Square root.
5^2 = 25 so sqrt25 = 5