1. 1.4: Write Equations and Inequalities
Do NOW
Write an expression for the phrase: 4 times the difference of 6 and the number y
The temperature was –4°F in the morning and rose to 10°F by noon. What is the temperature at noon?
Solve –1/4(–8)(–2x)
Solve (5/8) ÷ (–35/24)
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1.4: Write Equations and Inequalities

2. 1.4: Write Equations and Inequalities
Page 18 4)
x + 8 6)
50/h 8)
15 + x
10)
p2 – 3
12)
3w + 5
14) C
16)
5 – p
18)
20 + j
20)
m/60
32)
98g; 1960 tons
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1.4: Write Equations and Inequalities

3. 1.4: Write Equations and Inequalities
Page 122
14)
–10
16)
–5.4
18)
7/60
20)
–11
22)
–8.6
24)
–4/3 or –1 1/3
26) –8
28)
–3.4
30) 60
32)
–28y
34)
–20z
36) 15
38)
67/22 or 3 1/22
40)
1/4
42)
C = –2p + 130; $122
44)
–26
46)
347 m
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1.4: Write Equations and Inequalities

4. WRITE EQUATIONS
& INEQUALITIES
Section 1.4

5. 1.4: Write Equations and Inequalities
Example 1
The difference of a number x and 11 is equal to 35. Write the equation and solve.
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1.4: Write Equations and Inequalities

6. 1.4: Write Equations and Inequalities
Example 2
The sum of 12 and the quantity 8 times a number k is equal to 48. Write the equation and solve.
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1.4: Write Equations and Inequalities

7. 1.4: Write Equations and Inequalities
Your Turn
The product of 9 and the quantity 5 more than a number x is 18. Write the equation and solve.
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1.4: Write Equations and Inequalities

8. 1.4: Write Equations and Inequalities
Review
Little Suzy pays $0.05 for every text message she sends. Write an expression that represents how much money he spends on text messages.
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1.4: Write Equations and Inequalities

9. 1.4: Write Equations and Inequalities
Example 3
Little Suzy pays $0.05 for every text message she sends. Last month, her bill for text messaging was $25. Write an equation that represents how many text messages did Little Suzy send last month?
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1.4: Write Equations and Inequalities

10. 1.4: Write Equations and Inequalities
Your Turn
Little Johnny has a job at Taco Bell. He puts $25 into his savings account every week. If he had $75 in the account before he began working, write an equation that could be used to determine how many weeks, w, it would take him to have $500 in his account?
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1.4: Write Equations and Inequalities

11. What do these signs mean?
>
Greater than, more than
Greater than OR equal to;
At least; No less than ≥
<
Less than, fewer than
Less than OR equal to;
At most; No more than ≤
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1.4: Write Equations and Inequalities

12. 1.4: Write Equations and Inequalities
Inequalities Steps
X typically comes first or is in the middle of the compound
> represents greater than; more than
> represents greater than or equal to; at least; no less than
< represents less than; fewer than
< represents less than or equal to; at most; or no more than
Don’t forget to label
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1.4: Write Equations and Inequalities

13. 1.4: Write Equations and Inequalities
Example 4
Check whether 4 is a solution to 2x + 5 > 12.
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1.4: Write Equations and Inequalities

14. 1.4: Write Equations and Inequalities
Example 5
Check whether 3 is a solution to 2x + 5 > 12.
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1.4: Write Equations and Inequalities

15. 1.4: Write Equations and Inequalities
Your Turn
Check whether 3 is a solution to
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1.4: Write Equations and Inequalities

16. 1.4: Write Equations and Inequalities
Example 6
Write an inequality of the quotient of a number x and 12 is fewer than 30 and solve.
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1.4: Write Equations and Inequalities

17. 1.4: Write Equations and Inequalities
Example 7
This season, Little Bobby has 125 at-bats in baseball. By the end of the season, he wants to have at least 140 at-bats. How many more at-bats does he need to reach her goal? Write the equation and solve.
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1.4: Write Equations and Inequalities

18. 1.4: Write Equations and Inequalities
Your Turn
Little Johnny’s older brother works at American Eagle and earns $275 per week plus a 4% commission. He desperately wants a new stereo for his car that costs $395. Not including taxes, what is the minimum he would have to sell to earn enough money for the stereo?
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1.4: Write Equations and Inequalities

19. 1.4: Write Equations and Inequalities
Assignment
Page all, all, even, : Write and SOLVE the equation/inequality
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1.4: Write Equations and Inequalities