Answer: Each adult’s meal costed $15
Step-by-step explanation:
This situation can be modeled by the following equation:
2a + 3c = 42, where a = the cost of an adult’s meal, and c = the cost of a child’s meal
Since we know from the problem that a child’s meal costs $4, we know c:
2a + 3(4) = 42
At this point, we can just solve the resulting equation for a:
2a + 3(4) = 42
= 2a + 12 = 42 (simplify 3(4))
= 2a = 30 (subtract 12 from both sides)
= a = 15 (divide both sides by 2)
So, the cost of each adult’s meal was $15.