Outline a Proof of the Following Statement by Writing the "Starting

Essay

Outline a proof of the following statement by writing the "starting point" and the "conclusion to be shown" in a proof of the statement.
$\forall \text { real numbers } r \text { and } s \text {, if } r \text { and } s \text { are rational then } r - s \text { is rational. }$
That is, complete the sentences below. Proof: Suppose______
We must show that__________