In order to solve this linear equation, we need to group all the variable terms on one side, and all the constant terms on the other side of the equation. In our example, - term 2, will be moved to the right side. Notice that a term changes sign when it 'moves' from one side of the equation to the other. Therefore, the answer is x=-9
$1 for 2 cups. 14 cups in an afternoon means they got $7. If they did this for three days (7 x 3) they'd have 21 dollars. it is not reasonable because 21 is nowhere near 50.