Answer:
only C is non-linear
Step-by-step explanation:
A linear equation is of the form;
y = mx + c
we have single powers of x and y; also, there is no product of x and y
Thus, we have;
a; 12x + 3y = 7
y =( -12x + 7)/3
this shows we have a linear equation
b. y + x = 4x + 5
y = 4x-x + 5
y = 3x + 5
This is a linear equation
c. y = 8/x^2
This is non-linear; we already have one power of x as 2
