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:
105 km
Step-by-step explanation:
Written as a proportion, the ratio of km to cm will be the same for both distances:
(x km)/(17.5 cm) = (15 km)/(2.5 cm)
x km = (15 km)(17.5/2.5) = 105 km
105 actual kilometers are represented by 17.5 cm on the map.
Answer:
3t + 5.25b ≥ 340
Step-by-step explanation:
Answer: it will take 25 months
Step-by-step explanation:
Let x represent the number of months that it will take for the cost of both plans to be the same.
Cell phone Plan A costs $70 per month and comes with a free $500 phone. This means that the total cost of x months with plan A would be
70 × x = $70x
Cell phone plan B costs 50 per month but does not come with a phone. If you buy the 500 phone and choose plan B, then the total cost of x months with plan B would be
500 + 50 × x = 500 + 50x
To determine the number of months until your cost is the same as Plan A's, we would equate both costs. It becomes
70x = 500 + 50x
70x - 50x = 500
20x = 500
x = 500/20 =25
Answer:

Step-by-step explanation:
The slope-intercept form of an equation of a line:

m - slope
b - y-intercept
The formula of a slope:

We have the points from the graph (-5, 2) and (5, -1).
Substitute:

We have the equation in form:

Put the coordinates of the point (5, -1) to the equation:


<em>add 3/2 to both sides</em>
