1. 1.4: Rewriting Formulas and Equations
Page 6 3)
{–2, –1, –3/4, 9/2, 5}
All: Rational; –2, –1, 5: Integer; 5: Whole, Natural 5)
{–5/4, –2/3, 1, √3, 2}
√3: Irrational; –5/4, –2/3, 1, 2: Rational; 1, 2: Whole, Natural, Int 7)
{–1, –0.4, 0, 3/2, √10}
√10: Irrational; –1, –0.4, 0, 3/2: Rational; –1: Integer; 0: Whole 9) B
11)
Associative Property of +
13)
Communicative Property of x
15)
Distributive Property
49)
Always
51)
Sometimes
53)
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1.4: Rewriting Formulas and Equations

2. 1.4: Rewriting Formulas and Equations
Page 21 3)
{3} 7)
{6}
11)
{4}
15)
{18}
19) B
21)
{1}
23)
25)
{–7}
27)
{–4/3}
29)
31)
{–8/3}
33)
37)
{–2}
41)
3/7 should be multiplied by 7/3
45)
{60}
49)
{5/3}
63)
{Ø}
64)
{All Reals}
65)
66)
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1.4: Rewriting Formulas and Equations

3. Rewrite Formulas and Equations
Section 1.4
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1.4: Rewriting Formulas and Equations

4. 1.4: Rewriting Formulas and Equations
Literal Equations
A literal equation is an equation that has more than one variable
Literal in Latin means “letter.”
Solve for the missing variable and substitute
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1.4: Rewriting Formulas and Equations

5. 1.4: Rewriting Formulas and Equations
Steps
Move the term and variables onto one side
Isolate the variable
Simplify
Check
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1.4: Rewriting Formulas and Equations

6. 1.4: Rewriting Formulas and Equations
Example 1
Solve the formula d = rt for t. Then, find the time it takes to travel 312 miles at an average rate of 48 miles per hour.
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1.4: Rewriting Formulas and Equations

7. 1.4: Rewriting Formulas and Equations
Example 2
Solve the formula P = 2l + 2w for w. Then, find the width of a rectangle with a length of 12 meters and perimeter of 41 meters.
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1.4: Rewriting Formulas and Equations

8. 1.4: Rewriting Formulas and Equations
Your Turn
Using this formula given, V = 1/3πr2h, solve for h. Then, find the height if the volume is 900 cubic inches3 and the radius is 3 inches. Leave answers in π.
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1.4: Rewriting Formulas and Equations

9. 1.4: Rewriting Formulas and Equations
Example 3
Solve 2y + xy = 6 for y.
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1.4: Rewriting Formulas and Equations

10. 1.4: Rewriting Formulas and Equations
Example 4
Solve 2xy – x = 3 for y.
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1.4: Rewriting Formulas and Equations

11. 1.4: Rewriting Formulas and Equations
Your Turn
Solve 4x + 7y + 5xy = 0, x = 1 for y.
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1.4: Rewriting Formulas and Equations

12. 1.4: Rewriting Formulas and Equations
Example 5
The HSPVA School Store is selling spirit shirts for $15 each and sweatshirts for $22 each. Write an equation for the bookstore’s revenue R from selling m t-shirts and n sweatshirts. Then, write an equation for m and figure out how many t-shirts can be bought if the Revenue totals $274 for the day and the amount of sweatshirts bought was 7.
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1.4: Rewriting Formulas and Equations

13. 1.4: Rewriting Formulas and Equations
Assignment
Pg 30: 3-31 odd (omit 27)
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1.4: Rewriting Formulas and Equations