Answer:
a + c = 30
8a + c = 100
a=10, c= 20
Step-by-step explanation:
cost = 8a + 1c since it is 8 dollars for adult and 1 for child where a is the number of adults and c is the number of children
a+c = 30 since we know that 30 adults and children went
100 = 8a + 1c and it cost 100 dollars
Let c =30 -a
100 = 8a + (30-a)
100 = 7a +30
Subtract 30 from each side
70 = 7a
Divide by 7
10 =a
Then a+c = 30
10+c = 30
c = 30-10
c = 20
eqn1 : a +c=30
eqn2: 8a+c=100
20 children and 10 adults
n = -1
1 - 8n - 8 = -7n - 6n - 12
Simplify
-8n - 7 = -13n - 12
Add 7 to both sides
-8n = -13n - 5
Add 13n to both sides
5n = -5
Divide both sides by 5
