Usando proporciones, se encuentra que 400 africanos han participado.
En total, hay x participantes.
de los corredores son europeos, o sea:

Los americanos son la dècime parte de los europeos, o sea:

Los africanos son la quinta parte de los americanos, o sea:

En la carrera han inscritos 24 000 participantes, o sea,
. Por eso, la cantidad de africanos es:

Para obtener más información sobre las proporciones, puedes visitar a brainly.com/question/24615636
Answer:
240 miles
Step-by-step explanation:
Step 1
We find the constant rate at which the family travels
Speed(Rate) = Distance/Time
A Family travels at a constant rate and drove 420 miles in 7 hours.
Speed(Rate) = 420 miles/7 hours
= 60 miles per hour
Step 2
If they drive at the same speed ,How many miles will they drive in the next four hours.?
We are to finally calculate the distance for the next 4 hours
Distance = Speed × Time
Speed = 60 miles per hour
Time = 4 hours
Distance = 60 miles per hour × 4 hours
Distance = 240 miles
Therefore, for the next 4 hours the number of miles they would drive is 240 miles
If you're completing the square the answer is in the image.
expression
x^2 + 5x - 5=ax^2+bx+c
a=1, b=5, c=-5, and you can solve it that way.
Answer:
= 3,000,000,000
Step-by-step explanation:
Step 1- Multiply
5×6= 30
Once you've multiplied, you can just add the 0's to 30.
There are a total of eight 0's.
Once you've added all the 0's, you'll get 3,000,000,000.
Let x be the shorter side, and y be the longer side
There would be 4 fences along the shorter side, and 2 fences along the longer side
4x + 2y = 800
Rewrite in terms of y:
y = 400 − 2x
The area of the rectangular field is
A = x*y
Replace Y with the equation above:
A = x(400 − 2x)
A = − 2x^2 + 400x
The area is a parabola that opens downward, the maximum area would occur at the parabola vertex.
At the vertex
x = −b/2a
= −400/[2(−2)]
= 100
y = 400 −2x
y = 400 -2(100)
y = 400-200
y = 200
The dimension of the rectangular field that maximize the enclosed area is 100 ft x 200 ft.