ariewilliam421
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A group of children and their parents went to the skating rink.There were a total of 30 people in the group, The cost for each adult was $12 and the cost for each child was $8. The total amount paid was $280. Let A represent the number of adults and C represent the number of children.

Respuesta :

apologiabiology
c=number of children
a=number of adults
total number os 30 so 
a+s=30

cost for all adult=12a
cost for all child=8c
total cost=12a+8c
280=12a+8c
divide by 4 to make it easier
70=3a+2c

so we have
a+c=30
3a+2c=70
multiply firse equation by -2 and add to second equaiton

-2a-2c=-60
3a+2c=70 +
1a+0c=10

a=10
subsitute
a+c=30
10+c=30
c=20

20 childeren
10 adults



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