A group of 45 people attended a ball game. There were twice as many children as adults in the group. Set up a system of equations that represents the numbers of adults and children who attended the game and solve the system to find the number of children who were in the group.

a+c=45 c=2a;15 adults,30 children
a+c=45 a=c+2;30 adults;22 children
a+c=45 c=a+2; 22 adults;30 children
a+c=45 a+2c; 30 adults;15 children

1 answer

The correct system of equations would be:

a + c = 45
c = 2a

To solve this system, you can substitute the second equation into the first equation:

a + 2a = 45
3a = 45
a = 15

Then, you can substitute the value of a back into the second equation to find the value of c:

c = 2(15)
c = 30

Therefore, there were 30 children in the group.