Hwo do i put this sentence into mathematical way. "the difference of a number and eighty is equivalent to the sum of double the number and twelve? "

Identify the converse of the following conditional: if a point is in the first quadrant, then its coordinates are positive. if the coordinates of a point are not positive, then the point is not in the first quadrant. if the coordinates of a point are positive, then the point is in the first quadrant. if a point is in the first quadrant, then its coordinates are positive. if a point is not in the first quadrant, then the coordinates of the point are not positive.

The graph represents the gallons of water in a water tank with respect to the number of hours since it was completely filled

Can someone me i’m confused. will give brainliest and a whole bunch of points