1. EXAMPLE 1
Standardized Test Practice

2. EXAMPLE 1
Standardized Test Practice
SOLUTION
Write and solve a two-step equation to find the number of flamingos. Write a verbal model. Let n be the number of additional flamingos.

3. Standardized Test Practice
EXAMPLE 1
Standardized Test Practice
2370 = 395n
Write an algebraic model.
2370 – 1580 = 395n – 1580
Subtract 1580 from each side.
790 = 395n
Simplify.
790
395
395n =
Divide each side by 395.
2 = n
Simplify.

4. EXAMPLE 1
Standardized Test Practice
ANSWER
The zoo can buy 2 new flamingos next year. An equation for finding the number of flamingos is 2370 = 395n The correct answer is B.

5. GUIDED PRACTICE
for Example 1
Feeding Costs 1.
It costs a zoo $1150 this year to feed tortoises. Each new tortoise costs $575 to feed. A zoo’s budget for tortoise food next year is $2875. How many new tortoises can the zoo buy next year?
ANSWER
The Zoo can buy 3 new tortoises next year

6. Writing and Solving a Two-Step Equation
EXAMPLE 2
Writing and Solving a Two-Step Equation
The sum of 4 times a number plus –6 is 14. What is the number?
4 times a number and –6 is 14.
Write a verbal model.
4 n + (–6) = 14
Translate.
4n – 6 = 14
Write equation.
4n – =
Add 6 to each side.
4n = 20
Simplify. 4n 4 = 20
Divide each side by 4.
n = 5
Simplify.
ANSWER
The number is 5.

7. EXAMPLE 3
Writing and Solving a Two-Step Equation
Reading
You want to find how many pages you need to read per week in order to finish several books in six weeks. The books have a total of 1244 pages. You have already read 500 pages. How many pages do you have to read per week?

8. Writing and Solving a Two-Step Equation
EXAMPLE 3
Writing and Solving a Two-Step Equation
SOLUTION
Let p be the number of pages to read per week.
1244 = 6p + 500
Write an algebraic model.
1244 – 500 = 6p – 500
Subtract 500 from each side.
744 = 6p
Simplify.
744 = 6p 6
Divide each side by 6
124 = p
Simplify.
ANSWER
You have to read 124 pages per week.

9. GUIDED PRACTICE
for Examples 2 and 3
2. The difference of six times a number and 9 is -3.
What is the number?
ANSWER
The number is 1.

10. GUIDED PRACTICE
for Examples 2 and 3
3. What If?
Suppose in Example 3 that you have read 714 pages and have five weeks left. How many pages do you have to read per week?
ANSWER
You have to read 106 pages per week