Page 622 - Algebra 1

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Error Analysis Two students simplified c - 6 + 6 - c . Which student is correct? Explain the error.
Multi-Step A farmer has a rectangular plot of land with an area of x2 + 22x + 72 square meters. He sets aside x2 square meters for grazing and 2x - 8 square meters for a chicken coop.
a. Write a simplified expression for the total fraction of the field the farmer has
set aside.
b. Estimate About what percent of the field has the farmer set aside if x = 30?
12 _2c _
Student A
_ 2(c - 6)
2c - 12 c-6
=2
c-6
Student B
2c + 12 _
c-6 2(c+6) =-2
_ c-6
Geometry Write a simplified expression for the total fraction of the larger rectangle that the triangle and smaller rectangle cover.
Find the product of (√ 4 - 6)2.
Analyze Why is it necessary to understand factoring when dealing with rational
5x
expressions? _
Multi-Step The base of triangle ABC is x2 + y. The height is 4x + 2xy . What is the
area of triangle ABC? x3 + xy a. Multiply the base of the triangle by its height.
b. Multiply the product from part a by _1 . 2
Error Analysis Two students tried to find the axis of symmetry for the equation y = 8x + 2x2. Which student is correct? Explain the error.
2x 2x
2x
x - 2
2x + 18
Student A
____ x = -b = -2 = -2 = - 1
2a 2(8) 16 8
Student B
__
x= -8 =-8=-2
2(2) 4
3 4
Space If it were possible to play ball on Jupiter, the function y = -13x2 + 39x would approximate the height of a ball kicked straight up at a velocity of
39 meters per second, where x is time in seconds. Find the maximum height the ball reaches and the time it takes the ball to reach that height. (Hint: Find the time the ball reaches its maximum height first.)
Measurement The coordinates of two landmarks on a city map are A(5, 3) and B(7, 10). Each grid line represents 0.05 miles. Find the distance between landmarks A and B.
Lesson 91 607