The answer is 32. you would multiply 8 times 4 which is 32 feet.
So we have the following system of equations:
We need to solve it by substitution. This means that we have to take the expression for x given by the second equation and replace x with it in the first equation:
So y=-1. If we use this value in the second equation:
So we have x=2 and y=-1 which means that there's one solution. Then the correct answer is A and the solution is (2,-1).
Answer:
Step-by-step explanation:
1
Let
be the temperature of the body
hours after 1:30 PM. Then
and
.
Using Newton's Law of Cooling,
, we have
. Now let
, so
, so
is a solution to the initial value problem
with
.
By separating and integrating, we have
.
≈ 95 minutes. Thus the murder took place about 95 minutes before 1:30 PM, or 11:55 AM.
The speed at which the distance is covered by the two vehicles is the sum of their speeds:
... (truck speed) + 1.5×(truck speed) = 2.5×(truck speed)
The time required to cover the distance is inversely proportional to speed, so is
... (2.5 hours)/2.5 = 1.0 hours
It takes 1.0 hours for the vehicles to meet.
_____
The speed of the truck is (145 mi)/(2.5 h) = 58 mi/h
The speed of the car is 1.5 × 58 mi/h = 87 mi/h.
The speed at which they move toward each other is
... 58 mi/h + 87 mi/h = 145 mi/h
So, the time it takes to cover 145 miles is
... (145 mi)/(145 mi/h) = 1.0 h