<span>The expression 2x + 50 represents the elevation above sea level of the climber. It can be written as a function as follows:
f(x) = 2x + 50 where f(x) is the height and x is time.
We can obtain the initial height when we set time 0 in which the climber has not started climbing yet. Therefore, the initial height of the climber would be 50 meters above sea level.</span>
P+A=420
P=6A
6A+A=420
7A=420
A=60
P=6(60)
P=360
CHECK:
P+A=420
360+60=420
420=420
There would be an 85% change, you just add then divide them and you get 85% as your answer.