Page 380 - Algebra 1

Lesson Practice
Practice
Distributed and Integrated
Tell whether each equation represents a direct variation. If the equation is a direct variation, find the constant of variation.
(Ex 1) a.y-12=x
c. 2xy=8
Tell whether each set of ordered pairs represents a direct variation.
(Ex 2)
e. (3, 10), (12, 40), (9, 30) f. (10, 4), (12, 6), (14, 8)
g.
(Ex 3)
h.
(Ex 4)
i.
(Ex 5)
Write an equation for a direct variation that includes the point (9, 72).
The number of boys in a class varies directly with the number of girls. One class has 6 girls and 18 boys. How many boys will be in a class with 8 girls?
The volume of a box with a fixed base area varies directly with its height. A box with a height of 4 centimeters has a volume of 29 cubic centimeters. Graph this relationship, and then use the graph to estimate the volume of a box that is 3 centimeters tall.
Solve.
1. -4_3 +3_3 x=13_1 2. 0.3x-0.02x+0.2=1.18
(26) 4 5 4 (26)
3. Solve the following equation for p: 7p + 3w = w - 12 - 3p.
(26)
4. Write the prime factorization of 315. (38)
5. What percent of 160 is 88? (42)
6. What number is 140 percent of 70? (42)
7. Twenty percent of what number is 18? (42)
*8. Tell whether the equation _y = x represents a direct variation. (56) 11
*9. Tell wheth_er the equation 3y = x represents a direct variation.
(56)
(10x3 )2 3 22
10. Simplify y (-2x y ) . (4 0)
_y
b. -3=x
d. 3y=x
11. Market Research An automobile manufacturer sent out 22,000 questionnaires to (42) a sample of their customers who bought a new car from them this year. 63% of
the customers who received the questionnaires filled them out and returned them. How many customers returned their questionnaires?
Lesson 56 365