Real-world problems do not often present themselves in mathematical terms. The mathematics often has to be inferred from the context of the sentence. A rock climber is climbing a rock at Hueco Tanks State Park outside of El Paso, Texas. The altitude of the rock climber can be found using the equation a = 4,600 + 200h, where h represents the number of hours climbed, and a represents the climber's altitude above mean sea level.

Click and drag the part of the equation to the statement that best describes that part.  A rock shop sells souvenirs of special types of rocks. They sell granite, marble, and sandstone. The pricing manager uses the equation 16g + 4s = 24 to determine the amount of granite and sandstone that should be included in each rock bag, which costs \$24.

Click and drag the part of the equation to the statement that best describes that part. Practice

Which of the following scenarios could be used to describe the equation c = 3.75s + 15?

1. The total cost of a stock transaction is \$3.75 per share of stock, plus a \$15 fee.
2. The total cost of a vehicle with s passengers to enter the state park is \$18.75.
3. The total cost for s concert tickets is \$15 per ticket, plus a convenience fee of \$3.75.
4. An international telephone call that lasts s minutes costs a total of \$3.75 per minute, plus a \$15 connection fee.

Interactive popup. Assistance may be required.

In the equation, the constant term may represent a fixed fee, and the coefficient of the x term may represent a rate of change. Which of the following scenarios could be used to describe the equation 4x + 6y = 20?

1. A snack bag contains caramel popcorn that costs \$4 per pound and cashews that cost \$6 per pound. The snack bag costs \$20.
2. Adult tickets cost \$6 each and children's tickets cost \$4 each. Mrs. Merriwether purchased \$20 worth of tickets.
3. Hamburger and french fry combo meals cost \$10 each. Jonathan purchased \$20 worth of combo meals.
4. Sybil works at a snack bar. Jellybeans cost \$4 per pound and sesame sticks cost \$6 per pound. Last week, Sybil worked 20 hours.
Interactive popup. Assistance may be required.

The coefficients 4 and 6 may represent a rate, if x and y represent amounts of something. 