1. 2-7 COURSE 2 LESSON 2-7 (For help, go to Lesson 2-3.) Write and solve an equation for each sentence. 1.Seven fewer than a number is 12. 2.The sum of 9 and a number is equal to 36. 3.Twenty-seven is 10 less than a number. 4.Seventeen more than a number is 5. Write an Equation

2. Solutions 1.n – 7 = 122.9 + n = 36 n – 7 + 7 = 12 + 7 9 – 9 + n = 36 – 9 n = 19 n = 27 COURSE 2 LESSON 2-7 3. 27 = n – 10; n = 27 + 10 = 374. n + 17 = 5; n = 5 – 17 = –12 2-7 Write an Equation

3. Of the 64 students going to the science fair, 36 will ride in a bus. The others will ride in vans that each carry 6 students. How many vans are needed? COURSE 2 LESSON 2-7 36 of the 64 students going to the science fair will ride in a bus. The rest of the students will ride in vans that can carry 6 students each. You need to find the number of vans that are needed. There are two groups of students going to the science fair: those riding in a bus, and those riding in vans. The sum of the two groups cannot be less than the total number of students. Write an equation and solve the problem. 2-7 Write an Equation

4. (continued) COURSE 2 LESSON 2-7 36 + 6v = 64 Solve the equation. 36 – 36 + 6v = 64 – 36Subtract 36 from each side. 6v = 28 or v = 4.6Simplify. Since you cannot have 4.6 vans, 5 vans are needed. Words students plus students times number equals total in the in each of vans students bus van Let v = the number of vans needed. Equation 36 + 6 v = 64 2-7 Write an Equation

5. (continued) COURSE 2 LESSON 2-7 Each van will carry 6 students. The total number of students able to ride in the vans and the bus is 36 + 5 6, or 66 students. If 4 vans are used, the total is 36 + 4 6, or 60 students. Since this is less than the total students traveling, the answer checks. 2-7 Write an Equation

6. Lindsey has saved $12 to go to the movies. This is $3 more than twice the cost of a movie. What is the cost of a movie? COURSE 2 LESSON 2-7 Think about the information and what you are being asked to find. Lindsey has $12, and this is $3 more than twice the cost of a movie. You are asked to find the cost of a movie. Since you are given the relationship between the numbers, an equation can help you solve the problem. 2-7 Write an Equation

7. (continued) COURSE 2 LESSON 2-7 The cost of a movie is $4.50. Words two times cost of a plus three equals total amount movie of money Let c = the cost of a movie. Equation 2 c + 3 = 12 2c = 9 Simplify. c = 4.5Simplify. 2c + 3 = 12 2c + 3 – 3 = 12 – 3 Subtract 3 from each side. Divide each side by 2. 2c22c2 9292 = 2-7 Write an Equation

8. (continued) COURSE 2 LESSON 2-7 To check the solution, use 4.5 for the cost of a movie. Since 2 4.5 + 3 = 9 + 3 = 12, the answer is correct. 2-7 Write an Equation

9. Solve each problem by writing and solving an equation. 1.Ravi bought 3 identical shirts and paid a sales tax of $2.84. The total cost was $50.18. What was the cost of each shirt? 2.In 1976, Jimmy Carter received 58 fewer electoral votes than 5 times the number received by John Adams in 1796. Carter received 297 electoral votes. How many did Adams receive? 3s + 2.84 = $50.18; $15.78 5h = 297 + 58; 71 votes COURSE 2 LESSON 2-7 2-7 Write an Equation