Tired of being single, but how do u do this problem?

The lines shown below are parallel. if the green line has a slope of -1, what is the slope of the red line

Me. i can't figure out this question. give an explanation too. .

Amountain climber starts a climb at an elevation of 453 feet above sea level at his first rest stop he has climbed 162 feet and by his second rest stop he has climbed another 207 feet its getting late in the day so the climber starts his way down if the climber desends 285 feet how much does he need to ascend or descend to return to the original starting point