15 // Write a program in C++ to find the result of the next series and according to the concept of functions L=4x+10

1. Write a c++ code that takes two integer numbers as inputs, then adds them using a function called add(x,y), then subtracts them using a function called subtract(x,y), and outputs the results in an understandable way.

Define an user defined C++ function to find out the average of four integer numbers. The function should take the values those are passed as parameters and returns the average to the main function. Sample input: Enter four integers: 10 20 30 42 Average: 25.50

Please use C++. Write the following function declarations as they would appear on single lines above main() . a.Declare a function doTheLogic that takes a boolean variable, a, and returns a boolean. b. Declare a function doTheLogic that takes a boolean variable, a, and a boolean variable, b, and returns a boolean. c.Declare a function doTheLogic that takes a boolean variable, a, and a boolean variable, b, and a boolean variable, c, and returns a boolean. d. What is this technique called? e. Why would you declare several functions with the same name?