I hope this picture helps, but next time try to chose a number to cancel out the fraction. Example, y=1/3x+4 chose 3,6,9 and other multiples of 3.
<span> -k - (-8k) = -k + 8k = 7k</span>
30 = 60% of x
x being our variable, we need to figure out what x equals. Use the formula I put in the attachment. Multiply 30 by 60, and then divide the product by 100. That will give you the answer :)
Average change in altitude per minute
216.12÷2.4
=90.05m