How do I do this I genuinely don’t understand

Question

The expression 𝟐𝟑𝒂 + 𝟏𝟓𝒄 is the cost (in dollars) for 𝒂 adults and 𝒄 children to enter an aquarium. How much does it cost for an adult? a child? Find the total cost for 4 adults and 24 children.

Answer 1

There are 2 variables in this equation. a represents the number of adults visiting the aquarium. c represents the number of children going to the aquarium.

The complete equation (with units) looks like this: $23*a + $15*c = Total Cost of visiting the aquarium (in dollars).

Remember that if no operation is written, we assume multiplication.

Based on the equation, we know that each adult costs $23 dollars and each child costs $15. I make sense of this by thinking about what your equation would equal if you had 1 adult and 0 children ($23 * 1 + 0 = $23) or 0 adults and 1 child (0 + $15 * 1 = $15). Now that we know the price for each person, we can solve the problem.

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4 adults and 24 children are going to the aquarium.

You can think about how you would solve the problem in your head. I would multiply the 4 adults by $23 ($92 total) and then multiply the 24 children by $15 ($360 total). Then I would add those two numbers ($92 + $360 = $452). So, the total cost would be $452.

Here is what it looks like algebraically:

Original Equation: 23a + 15c = Total Cost

Substitute for Variables: 23*4 + 15*24 = Total Cost

Solve: 92 + 360 = $452.

The total cost of visiting the aquarium with 4 adults and 24 children is $452.