The answer is 60-5t<35-5t<_25t>5
Let x = mileage
98 >= 35 + .21x
Solving for x:
98 >= 35 + .21x
63 >= .21x
300 >= x
.
This says that if the total mileage is 300 miles or less he will be within his budget.
Answer:
You could use a graphing calculator to see the lowest point in the graph OR you could put that equation into it's completed squared form, which is (x-4)^2 -4. The opposite of -4 in the parentheses is positive 4, and the leftover -4 is the y value. So that also becomes (4,-4)
It isn't easy really but you can always divide the number out. For example 50% of 200 is 100 by dividing 200 by 2 or 25% of 100 is 25 by dividing 100 by 4 since 25% is equivalent to 1/4
You use sine, cosine, or tan