Answer is C or 21 because you have to plug in 5 into the equation
Answer:

Step-by-step explanation:
Given


Required:
Determine the time taken to return to the ground
From the equation given; height (h) is a function of time (t)
When the rocket returns to the ground level, h(t) = 0
Substitute 0 for h(t) in the given equation

becomes

Solve for t in the above equation

Factorize the above expression

Split the expression to 2

Solving the first expression

Divide both sides by -4



Solving the second expression

Add 30 to both sides


Divide both sides by 4



Hence, the values of t are:
and 
shows the time before the launching the rocket
while
shows the time after the rocket returns to the floor
Answer:
Erin ran 12.5 miles
Luis ran 7.5
In all they ran 20 miles.
Step-by-step explanation:
Erin: 5 x 3.5 = ?
Luis: 3 x 2.5 = ?
----------------------------
5 x 2.5 = 12.5 . Erin ran 12.5 miles
3 x 2.5 = 7.5 . Luis ran 7.5 miles
7.5 + 12.5 = 20 miles
They ran 20 miles all together.
Hope this helps!
Answer:
It increases by 2 1/2 o^F
Step-by-step explanation:
Hope this helped have an amazing day/month/year!