Answer:
the altitude of mountain climber b will be lower than the altitude of mountain climber A with number of hours greater than 7.5hrs.
Step-by-step explanation:
This talks about equalities in math,
We are told about Moutain climber A is at altiude of 250 feet and is descending at a rate of 30 feet per hour, this can be interpreted as
250 - 30h
Moutain climber B is at an altitude of 400 feet and is descending at a rate of 50 feet per hour, this can be interpreted as
400 - 50h
We were now asked how many hours the altitude of mountain climber b be lower than the altitude of mountain climber A, we can interpret this as
(400 - 50h) < (250 - 30h )
We can collect the like terms here
-50h + 30h < 250 - 400
-20h < - 150
The negatives sign can cancelled out, we have
Note that multiplying or dividing by a negative THE INEQUALITY SIGN MUST BE FLIPPED
20h > 150
h > 150/20
h > 7.5
Therefore, the altitude of mountain climber b will be lower than the altitude of mountain climber A with number of hours greater than 7.5hrs.