SOLUTION: The jurrascc zoo charges 10 for each adult and 7 for each child. The total bill for the 100 people was 790. How many adults and how many children are there

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Question 1049811: The jurrascc zoo charges 10 for each adult and 7 for each child. The total bill for the 100 people was 790. How many adults and how many children are there
Answer by advanced_Learner(501) About Me  (Show Source):
You can put this solution on YOUR website!
10a+7c=790
a+c=100
Solved by pluggable solver: SOLVE linear system by SUBSTITUTION
Solve:
+system%28+%0D%0A++++10%5Ca+%2B+7%5Cc+=+790%2C%0D%0A++++1%5Ca+%2B+1%5Cc+=+100+%29%0D%0A++We'll use substitution. After moving 7*c to the right, we get:
10%2Aa+=+790+-+7%2Ac, or a+=+790%2F10+-+7%2Ac%2F10. Substitute that
into another equation:
1%2A%28790%2F10+-+7%2Ac%2F10%29+%2B+1%5Cc+=+100 and simplify: So, we know that c=70. Since a+=+790%2F10+-+7%2Ac%2F10, a=30.

Answer: system%28+a=30%2C+c=70+%29.