Anticipatory Set/Opening Activity: Transparency 3-6
Solve each equation.
1. 8y + 3 + 5y =15
2. 4(x+3) -14= 7(x-1)
3. 2.8w -3= 5w- 0.8
4. 5(x+3) +2= 5x + 17
5. An even integer divided by 10 is the same as the next consecutive even integer divided by 5. What are the two integers?
6. Solve 6 (4+a) -3 = 4(a-3) + 2a
A. -1     B. 0     C. no solution     D. all numbers

Lesson Notes

Ratio: comparison of two numbers by division
*Remember rational numbers? (a/5) ratio rational
Proportion: equation stating that two ratios are equal
   ie: (5/10) = (1/2) if reduced forms are equal, ratios are a proportion

Example 1: Determine whether the ratios (7/8) and (49/56) form a proportion.

Cross-products: way to verify proportions

Ex2: Use cross products to determine whether each pair of ratios form a proportion
A. (4/5), (16/20)
B. (.25/.6), (1.25/2)

(5/10) = (1/2)
    5 and 2 are called the extremes
    10 and 1 are called the meansMeans-Extremes Property of Proportions
If (a/b) = (c/d), then ad=bc

Example 3: Solve the proportion (n/12)=(3/8)

Rate: ratio of two measurements having different units of measure Example: mpg, $/hr, mph, rpm, (mile/gallon)

Example 4: Josh finished 24 math problems in one hour. At that rate, how many hours will it take him to complete 72 problems?

Scale: ratio or rate used when making a model or drawing of something that is too large or too small to be conveniently drawn t actual size.

Example 5: To make a model of the Guadaloupe River bed, Hermie used 1 inch of clay for 5 miles of the river�s actual length. His model river was 50 inches long. How long is the Guadaloupe River?

Quiz 3:4-6 in 2 days
Homework p. 158 #1,2,11,13,14,16-19,21,22,24,25,27,28,30-35