The answer is 2( x - 4 ) = 9
Answer:
x = 112, y = 68, z = 112
Step-by-step explanation:
y = 68
x = z = 180 - 68 = 112
Use PEMDAS
P Parentheses first
E Exponents (ie Powers and Square Roots, etc.)
MD Multiplication and Division (left-to-right)
AS Addition and Subtraction (left-to-right)

For it to be non-linear, the rate of change cannot be constant. For the first table the rate is a constant 1 and the second table has a constant rate of -1. The 3rd and 4th tables have no constant rate and thus are non-linear.
The 4th table is increasing while the 3rd table is decreasing.
So the 3rd table, Set C, is the only non-linear negative association between x and y.