Answer:
The input for the equation y = 2x + 3 can be any real number. In this equation, "x" represents the independent variable, and "y" represents the dependent variable. You can substitute any value for "x" to find the corresponding value of "y". For example, if you choose x = 5, then the input is 5, and you can calculate the corresponding output (y) as follows:
y = 2(5) + 3
y = 10 + 3
y = 13
So, when the input (x) is 5, the output (y) is 13. Similarly, you can find the output for any other chosen input value by substituting it into the equation.