Exercise 4 Page 53

Practice makes perfect

a We want to write a real-life statements that involve each of the given inequalities. Let's start with the first given inequality.

x<3.5 Imagine that Anna bought a sleeping bag that is rated for use in temperatures as low as 3.5 ^(∘) C. This means that Anna will be cold inside her sleeping bag if the outside temperature drops below 3.5 ^(∘) C. Therefore, the temperatures at which Anna will be cold can be represented by the inequality x<3.5. Warm:& x ≥ 3.5 Cold:& x < 3.5

b Our friend's new SUV has 6 available seat belts. The number of people capable of safely riding in the car at the same time can be represented by the given inequality.

x ≤ 6 Notice that since we are talking about a number of people, x needs to be a natural number.

c The freezing point of sea water is -2^(∘) C. This means that the temperature of the ocean, if its surface is not frozen, can then be described by the given inequality.

x>-2

d Imagine that a group of friends wants to go to the zoo together. They get a group discount if their group has 10 or more people. Therefore, the number of people in the group necessary to get the discount can be represented by the last given inequality.

x ≥ 10 Notice that, since we are talking about a number of people, x needs to be a natural number.

Subchapter links

Communicate Your Answer p.53

Monitoring Progress p.54-57

Exercises p.58-60

Exercise 4 Page 53

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