What do you mean... $245???
5x^2 - 80 = 0
5x^2 = 80
x^2 = 80/5
x^2 = 16
x = sqrt 16
x = (4,-4) <===
Answer:
35 hours
Step-by-step explanation:
1 mile would be 7 hours- 7x5=35
Step-by-step explanation:
Our roots are 3, and i so our roots form
will be

Since i is one root, it conjugate, must be the other.
so we have

Simplify


So the function is

It will take one hour and thirty minutes.