Page 389 - Algebra 1

*22. Use a graphing calculator to solve the system of linear equations. (55)
2x + 3y = 12 -3x + 2y = 8
23. Tell whether the equation 7 + y = x represents a direct variation. (56)
Measurement The number of centimeters varies directly with the number of inches. book that is 9 inches?
3 4 24.
(56) A table is 25 inches, or 63.5 centimeters, long. How many centimeters long is a
25. Error Analysis Two students solve the following problem: (56)
A person’s age in months is directly proportional to the number of years the person has been alive. A 3-year-old is 36 months old. How many months old is a 24-year-old?
Which student is correct? Explain the error.
*26. Geometry The circumference of a circle is directly proportional to the length of (56) the radius. If the radius is 10 centimeters, the circumference is 20π centimeters.
What is the circumference of a circle with a radius of 29 feet?
*27. Multi-Step The fluid pressure on an object submerged in water varies directly with (56) the depth of the object. At 2 feet below the surface of the water, there is a fluid
pressure of 124.8 pounds per square feet.
a. Write the equation that represents this relationship.
b. Graph this relationship using a graphing calculator, and estimate the amount of pressure exerted on an object 9 feet below the surface.
c. Use the graph to estimate how deep an object is that experiences 312 pounds per square foot of pressure.
*28. Write Explain how the LCM is used when adding and subtracting fractions. (57)
*29. Multiple Choice What is the LCM of 15k11 and 36k6?
(57) A 3k6 B 180k6 C 180k11 D 540k17
*30. Clocks One clock chimes every 4x3y6 minutes. Another clock cuckoos every
(57) 2xy2 minutes. A third clock rings every 6x4y minutes. All the clocks just sounded
together. How many more minutes will it be until they all go off together again?
Student A
y = kx 36 = k · 3 12 = k
24 = 12x
x=2
Student B
y = kx 36 = k · 3 12 = k
y = 12 · 24 y = 288
374 Saxon Algebra 1