Question

writing equations for word problems
you can change a word expression into an algebraic expression by
converting the words to variables, numbers, and operation symbols.
to write a two - step algebraic expression for seven more than three
times a number, follow these steps.
① define the variable. \t\t\tlet n represent the number.
② ask yourself if there are any key words. \t\t\t\more than\ means add and
\t\t\t\t\t\t\t\t\t\t\times\ means multiply.
③ write an algebraic expression. \t\t\t$7 + 3\cdot n$
④ simplify. \t\t\t\t\t\t$7 + 3n$
solve.

1. three friends pay $4 per hour to rent a paddleboat plus $5 for

snacks. write an expression for the total cost of rental and
snacks. then evaluate the expression for 2 hours.

1. a lawn care service charges $10 plus $15 per hour to mow and fertilize

lawns. write an expression for the total cost of having your lawn
mowed and fertilized. then evaluate the expression for 4 hours

Explanation:

Step1: Define variable for Q4

Let \( h = \text{hours rented} \)

Step2: Write Q4 expression

Total cost = hourly cost + snack cost → \( 4h + 5 \)

Step3: Evaluate Q4 for \( h=2 \)

Substitute \( h=2 \): \( 4(2) + 5 = 8 + 5 = 13 \)

Step4: Define variable for Q5

Let \( h = \text{hours of service} \)

Step5: Write Q5 expression

Total cost = fixed fee + hourly cost → \( 10 + 15h \)

Step6: Evaluate Q5 for \( h=4 \)

Substitute \( h=4 \): \( 10 + 15(4) = 10 + 60 = 70 \)

Answer:

Q4: Expression is \( 4h + 5 \), value is 13
Q5: Expression is \( 10 + 15h \), value is 70