The sum of 9 and a number is twice a number plus 14. How would I write this as an equation?

Toyland is having a sale. all items are 20% off. how much will you save on an item that usually sells for 95$ explain your

Witch represents the inverse of the function f(x)=1/4x-12

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.