12 less then the quotient of 12 and a number z

How do you use the elimination method for this question? explain, because i really want to understand!

Need showing work for this problem 56.25 ×25.80

The input to the function is x and the output is y. write the function such that x can be a vector (use element-by-element operations). a) use the function to calculate y(-1.5) and y(5). b) use the function to make a plot of the function y(x) for -2 ≤ x ≤ 6.