Skip to main content
Ch. 1 - Equations and Inequalities
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Non è quello che usi tu?Cambia libro di testo
Capitolo 2, Problema 9

You are choosing between two gyms. One gym offers membership for a fee of \$40 plus a monthly fee of \$25. The other offers membership for a fee of \$15 plus a monthly fee of \$30. After how many months will the total cost at each gym be the same? What will be the total cost for each gym?

Guida verificata passo dopo passo
1
Define variables to represent the total cost for each gym after \( m \) months. Let \( C_1 \) be the total cost for the first gym and \( C_2 \) be the total cost for the second gym.
Write expressions for the total cost of each gym: For the first gym, the total cost is the initial fee plus the monthly fee times the number of months, so \( C_1 = 40 + 25m \). For the second gym, the total cost is \( C_2 = 15 + 30m \).
Set the two expressions equal to each other to find the number of months \( m \) when the costs are the same: \( 40 + 25m = 15 + 30m \).
Solve the equation for \( m \) by isolating the variable: subtract \( 25m \) and 15 from both sides to get \( 40 - 15 = 30m - 25m \), which simplifies to \( 25 = 5m \). Then divide both sides by 5 to find \( m \).
Once you have the value of \( m \), substitute it back into either \( C_1 \) or \( C_2 \) to find the total cost at that time.

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
4m

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

Linear Equations

Linear equations represent relationships where the variables appear to the first power and graph as straight lines. In this problem, the total cost for each gym can be expressed as a linear equation in terms of months, combining fixed fees and monthly charges.
Video consigliato:
06:00
Categorizing Linear Equations

Setting Equations Equal to Find Intersection

To find when two costs are the same, set their linear expressions equal and solve for the variable. This represents the point where the two cost lines intersect, indicating the number of months when both gym costs match.
Video consigliato:
3:43
Finding the Domain of an Equation

Substitution to Find Total Cost

After finding the number of months, substitute this value back into either linear equation to calculate the total cost at that time. This confirms the cost at which both gym memberships are equal.
Video consigliato:
5:48
Solving Systems of Equations - Substitution