4) A group of neighborhood families are planni fg a trip to the museum. Tickets are \( \$ 25 \) for adul and \( \$ 10 \) for children. The group also has a coupon for \( \$ 5 \) off. The expression \( 25 a+10 c-5 \) represents the total cost for \( a \) adult and \( c \) child tickets. Monica is purchasing tickets for 5 adults and कhthildren.

It looks like you're working on calculating the total cost for Monica's museum ticket purchase. Let's break it down step by step. ### Given: - **Adult ticket price:** \$25 - **Child ticket price:** \$10 - **Coupon discount:** \$5 off - **Monica's purchase:** 5 adults and \( c \) children ### Total Cost Expression: The general expression provided is: \[ \text{Total Cost} = 25a + 10c - 5 \] where: - \( a \) = number of adult tickets - \( c \) = number of child tickets ### Plugging in Monica's Values: Monica is purchasing tickets for **5 adults**. So, \( a = 5 \). Substitute \( a \) into the expression: \[ \text{Total Cost} = 25(5) + 10c - 5 \] \[ \text{Total Cost} = 125 + 10c - 5 \] \[ \text{Total Cost} = 120 + 10c \] ### Final Expression: \[ \boxed{120 + 10c} \] ### Interpretation: - **\$120** covers the cost for 5 adult tickets after applying the \$5 discount. - **\$10c** represents the cost for each child ticket multiplied by the number of children \( c \). ### Example: If Monica purchases tickets for **3 children**, the total cost would be: \[ \text{Total Cost} = 120 + 10(3) = 120 + 30 = \$150 \] ### Summary: The total cost for Monica's purchase can be calculated using the expression \( 120 + 10c \), where \( c \) is the number of children she is buying tickets for.