Answer:

Step-by-step explanation:
Let:

We need to eliminate one of the variables, so let's use elimination method. First multiply (1) by 2

Now subtract (2) from 2*(1) in order to eliminate x:

Solving for y:
Multiplying both sides by -1

Finally, replacing the value of y in (1)

Solving for x:
add 41 to both sides:

Multiply both sides by 1/2:

Answer:
25.13 square meters
Step-by-step explanation:
The formula for finding the circumference of a circle is πd or pi times the diameter
Diameter = 8 meters
Pi = 3.14
3.14 times 8 = 25.13
Answer:
Step-by-step explanation:
Gotta love these motion problems!!! This one is especially tricky! At noon, ship A is 180 km west of ship B. If ship A is traveling east, it is closing its distance to ship B (if ship B didn't move). But ship B is moving north at the same time. We need to find the distance each can travel in 4 hours using the d = rt formula. For ship A. We know it's moving at 35 km/h, so in 4 hours it can move d = 35(4) which is 140 km. Remember that is closing the distance to ship B. So it is 180 - 140 directly south of ship B. This problem will turn out to be a right triangle problem of sorts. The distance of 40 km serves as the base of this right triangle.
With ship B moving north at 25 km/hr, it can travel d = 25(4) which is 100 km. This serves as the height of the triangle. We are asked to find the rate at which the distance is changing 4 hours from their starting points. We know how far each can travel in those 4 hours, so in order to find the rate of change (which is the same thing as the slope!), we take the height and divide it by the base because that is the same thing as taking the rise over the run. 100/40 is 10/4 which is a rate of change of 2.5 km/hr
The formula to solve for this would be pi(r^2)xheight. Essentially what this formula does is it takes the are of the base (pi x r^2) and multiplies it by the height of the cylinder to find how many times the base can stack on itself until it reaches the top. This formula of base are times height works for all prisms with two bases. Here are the steps to solve:
1) plug in the values
- pi(15^2) x 45
2) solve for the base area of one of the circles
- pi(15^2)=225pi
3) multiply the base area by the height
- 225pi x 45 = 10,125pi
4) final answer: the tank can hold 10,125pi cubic feet of water
Answer:
A. 100$
Step-by-step explanation:
take 125 and multiply it to .20 (this is 20% in decimal form) this gives you 25. you know subtract 25 from 125 which gives you 100.