Answer:
Jimmy purchased 8 of the children's ticket and 7 of the adult's ticket.
Step-by-step explanation:
Let c = children tickets
Let a = adult tickets
Given the following data;
Number of tickets = 15
Total amount spent = $140
Cost of each children ticket = $7
Cost of each adult ticket = $12
*Translating the word problem into an algebraic equation (system)*
For the total number of tickets;
[tex] c + a = 15 [/tex] .........equation 1
For the total amount spent;
[tex] 7c + 12a = 140[/tex] ..........equation 2
*Solving the linear equation by using the substitution method*
Making c the subject in equation 1:
[tex] c = 15 - a[/tex] .......equation 3
Substituting "c" into equation 2;
[tex] 7(15 - a) + 12a = 140 [/tex]
Simplifying the equation, we have;
[tex] 105 - 7a +12a = 140[/tex]
[tex] 105 + 5a = 140[/tex]
Rearranging the equation, we have;
[tex] 5a = 140 - 105[/tex]
[tex] 5a = 35[/tex]
[tex] a = \frac {35}{5} [/tex]
a = 5 (For the $12 adult ticket).
To find the number of children tickets;
Substituting "a" into equation 3;
[tex] c = 15 - 7[/tex]
c = 8 (For the $7 children ticket).