The following machine doubles each input, subtracts 3, and then squares the result. (check photo) For example, if we input 5, then double 5 to get 10, subtract 3 to get 7, and finally square 7 to get 49.

-Write the expression that comes out of the machine if the input is 4.
Use ^ to express exponents. For example. 3² = 3^2

-If 121 is the output, what was the input?