Question

How do I do this? It's about systems of linear equations.

Answer 1

The cost of an adult ticket is $6

Explanation:

You can solve by either substitution or elimination

Let A rep. cost of an adult ticket

Let C rep. cost of a child ticket

9A+12C=$138

3(12A+4C=$100)

- 9A+12C=$138

36A+12C=$300

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-27A/-27 = -162/-27

A= 6