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6-8 Accelerated 6 Unit 7 Lesson 21

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IM K-5 Math
IM 6-8 Math
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Unit 7, Lesson 21

Representing Contexts with Equations

Accelerated 6

Practice

Problem 1

Match each situation to one of the equations.

A whale was diving at a rate of 2 meters per second. How long will it take for the whale to get from the surface of the ocean to an elevation of -12 meters at that rate?

A swimmer dove below the surface of the ocean. After 2 minutes, she was 12 meters below the surface. At what rate was she diving?

The temperature was -12 degrees Celsius and rose to 2 degrees Celsius. What was the change in temperature?

The temperature was 2 degrees Celsius and fell to -12 degrees Celsius. What was the change in temperature?

\(\text-12 + x = 2\)
\(2 + x = \text-12\)
\(\text-2x = \text-12\)
\(2x = \text-12\)

Problem 2

Starting at noon, the temperature dropped steadily at a rate of 0.8 degrees Celsius every hour.

For each of these situations, write and solve an equation, and describe what the variable represents.

How many hours did it take for the temperature to decrease by 4.4 degrees Celsius?
If the temperature after the 4.4-degree drop was -2.5 degrees Celsius, what was the temperature at noon?

Problem 3

ForLesson 14: Multiplying Rational Numbers

The markings on the number line are evenly spaced. Label the other markings on the number line.

A blank number line with 9 evenly spaced tick marks. Starting on the left, the fourth tick mark is labeled negative 30, the fifth tick mark is labeled 0, and the ninth tick mark is labeled 45.

Problem 4

ForLesson 10: Finding Differences

Find the value of each expression.

\(12 + \text-10\)
\(\text-5 - 6\)
\(\text-42 + 17\)
\(35 - \text-8\)
\(\text-4\frac12 + 3\)

Problem 5

ForLesson 1: Revisiting Proportional Relationships

Kiran mixes \(\frac34\) cup of raisins, 1 cup peanuts, and \(\frac12\) cup of chocolate chips to make trail mix. How much of each ingredient would he need to make 10 cups of trail mix? Explain your reasoning.

Illustrative Mathematics | v.360 Curriculum