Answer:

Step-by-step explanation:
Given
--- driver 1
-- driver 2

Required
The time they passed each other
First, we determine the function of driver 2.
We have that:
and 
So, the function is:


The time they drive pass each other is calculated as:


Collect like terms


Divide through by 2t

Solve for -8t

Solve for t


The average yearly growth rate of the height of the tree was 2.2 feet per year during the 7 1/2 years.
Answer:
The first one: 19/15a
second one: b²-4ac = D
Step-by-step explanation:
for first one: take LCM and solve
for second one: you square the expression on both sides then b²= D + 4ac, then when you take 4ac to the left hand side, it becomes b²-4ac= D