Algebra 1
7.5 Linear Inequalities
A. Graph the line y = 1/2x + 3
• When graphing inequalities in today's lesson, this line is called the boundary line.
• This line will be dotted when an inequality is strictly less than or greater than (< , >)
• This line will be solid when an inequality is less than or equal to, or greater than or equal to (≤ , ≥)
Oct 1­3:55 PM
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B. Graph the following inequalities
1. y >1/2x + 2
2. y ≥ 1/2x + 2
Oct 1­3:56 PM
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C. STEPS:
• First graph the related equation. This is the boundary line. It will be dotted when it is < or > and solid when ≤ or ≥.
• Then either intuitively shade to the side that satisfies or mathematically plug in an ordered pair and then shade to the side that satisfies. Oct 1­3:59 PM
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D. Graph the following inequalities
3. y < x + 4 4. y ≥ 1/2x ‐ 2 Oct 1­4:00 PM
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5. 3x + 4y < 16 6. 2x ‐ 8y ≤ 12 Mar 6­1:41 PM
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7. y > ‐ 2 8. x < ‐1
Mar 6­1:42 PM
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E. Applications: A firemen’s jubilee charges $4.50 for adults and $3.00 for children. The fire department needs to make at least $135 to cover all expenses. Using a for the adult ticket price and c for the children ticket price, write an inequality for the amount the fire department makes on ticket sales. If 25 child tickets are sold, how many adult tickets must be sold to cover expenses?
Oct 1­4:04 PM
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7.5 HW p. 407 #s 1 ­ 23, 55
Mar 6­3:03 PM
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