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IM: 7.5.14: Solving Problems with Rational Numbers (Lesson)

Last updated 9 months ago
8 questions
14.1: Which One Doesn’t Belong: Equations
1

Which equation doesn’t belong?

14.2: Draining and Filling a Tank
A tank of water is being drained. Due to a problem, the sensor does not start working until some time into the draining process. The sensor starts its recording at time zero when there are 770 liters in the tank.
1

Given that the drain empties the tank at a constant rate of 14 liters per minute, complete the table:

1

Later, someone wants to use the data to find out how long the tank had been draining before the sensor started. Complete this table:

1

If the sensor started working 15 minutes into the tank draining, how much was in the tank to begin with?

14.3: Buying and Selling Power
A utility company charges $0.12 per kilowatt-hour for energy a customer uses. They give a credit of $0.025 for every kilowatt-hour of electricity a customer with a solar panel generates that they don't use themselves.

A customer has a charge of $82.04 and a credit of -$4.10 on this month's bill.
1

What is the amount due this month?

1

How many kilowatt-hours did they use?

1

How many kilowatt-hours did they generate that they didn't use themselves?

1

Find the value of the expression without a calculator.

(2)(-30)+(-3)(-20)+(-6)(-10)-(2)(3)(10)

Then, write an expression that uses addition, subtraction, multiplication, and division and only negative numbers that has the same value.