Order the tasks needed to output 2 ^ (x + y) from first (1) to last (4).

Declaring the variable \(r\) is a necessary step but it must be the first action taken to establish a placeholder for the subsequent calculations. However, it does not contribute directly to the calculation of the expression \(2^{(x+y)}\) and therefore cannot be the last step.

Calculating \(r = x + y\) is an important intermediate step that occurs before multiplying by 2. This task establishes the correct value of \(r\), but it cannot be the final action since the expression is not yet in the correct form for output.

Outputting \(r\) is the last step in the process, but it should only occur after the correct value of \(r\) has been calculated by multiplying 2 with the previously computed sum \(x + y\). Thus, this task cannot precede the multiplication step, as the output would not reflect the intended result.