ALGEBRA TEST SOLUTIONS

A/ Factor Completely if Possible

1) 6a2b2 54b4

6b2(a2 9b2)

6b2(a 3b)(a + 3b)

2) c2 a2 10ab 25b2

c2 (a2 + 10ab + 25b2)

c2 (a + 5b)2

[c (a + 5b)][c + (a + 5b)]

[c a 5b][c + a + 5b]

3) 81 m4

(9 m2)(9 + m2)

(3 m)(3 + m)(9 + m2)

4) 3cx2 + 6cx 9c

3cx2 + 6cx 9c

3c(x2 + 2x 3)

3c(x + 3)(x 1)

5) 64 x6

(8 x3)(8 + x3)

(2 x)(4 + 2x + x2)(2 + x)(4 2x + x2)

6) a2b3 b3 + a2 1

b3(a2 1) + (a2 1)

(b3 + 1)(a2 1)

(b + 1)(b2 b + 1)(a 1)(a + 1)

7) 3x2 + 11x + 10

(3x + 5)(x + 2)

8) 25 x2 6x 9

25 (x2 + 6x + 9)

25 (x + 3)2

[5 (x + 3)][5 + (x + 3)]

[5 x 3][5 + x + 3] = (2 – x) (8 + x)

9) 7x2 27x 4

(7x + 1)(x 4)

  10) 3x3 + 24

3(x3 + 8)

3(x + 2)(x2 2x + 4)

 

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B/ Perform the Indicated Operations. Reduce to Lowest Terms.

1)

.

(2)

.

(3)

.

(4)

.

(5)

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C/ Solve These Equations and Check Your Answer(s).

1) 12 + 3(m + 4) = 5m 2

12 + 3m + 12 = 5m 2

24 + 3m = 5m 2

2m = 26 becomes m = 13

2) 8(n + 3) + (6 + 2n) = 2(n 2) + 5(5 + n)

8n + 24 + 6 + 2n = 2n 4 + 25 + 5n

10n + 30 = 7n + 21

3n = 9 becomes n = 3

3)

4(x + 2) 2(5 x) = x + 8

4x + 8 10 + 2x = x + 8

6x 2 = x + 8 becomes 5x = 10
so
x = 2

4)

11 t2 = 2t2 t 6 3t2 + 8t + 3

14 = 7t becomes t = 2 but t = 2 makes the last fraction's denominator = 0. There are no solutions.

5)

2x + 1 = 15 or 2x + 1 = 15

x = 7 or x = 8

6) x2 = 2x + 15

x2 2x 15 = 0

(x 5)(x + 3) = 0 becomes x = 5 or x = 3

7) 3x2 + 2x = 7

3x2 + 2x 7 = 0

using the quadratic formula

8)

.

x2 6x + 9 = 4(x 3)

x2 10x + 21 = 0 which becomes (x 7)(x 3) = 0
so x = 7 or x = 3

9) 3x + 2y = 16 (eq. 1)

7x + y = 19 (eq. 2)
becomes y = 19 7x

3x + 2(19 7x) = 16

3x + 38 14x = 16 becomes 11x = 22

x = 2 becomes y = 19 7x so y = 5

10) 4r2 + t2 = 25 (eq. 1)

2r + t = 7 (eq. 2) becomes t = 7 2r

4r2 + (7 2r)2 = 25

4r2 + 49 28r + 4r2 = 25

8r2 28r + 24 = 0

2r2 7r + 6 = 0

(2r 3)(r 2) = 0 so r = 3/2 or r = 2

both solutions work.

D/ Solve These Inequalities and Check Your Answers.

1) 3x + 2 < 5x 6

2x < 8 so x > 4

2) x2 + 4x > 12

x2 + 4x 12 > 0

(x + 6)(x 2) > 0

x < 6 or x > 2

3)

3(3x + 2) < 2(5x 4)

9x + 6 < 10x 8

x < 14 becomes x > 14

4)

1 < x < 13/5 and x > 5

5) | 3x 5| > 22

3x 5 < – 22 becomes 3x < – 17 so x < –17/3

3x 5 > 22 becomes 3x > 27 so x > 9

 

E/ Simplify these Radical Expressions:

1) =

2) =

=

=

3) =

d)
e) f)
g) h)

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F/ Rationalize these denominators

1)

2)

3)

4)

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G/ Simplify. Leave no negative exponents

1)

2)

3) 4)

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H/ Solve these word problems:

(remember to make a "let" statement and a table or diagram when helpful.)

1) The larger of two numbers exceeds the smaller by 4. Eight times the smaller decreased by four times the larger is 12. What are the two numbers?

solution:

2) The perimeter of a rectangle is 72 dm. Three times the width exceeds twice the length by 3 cm. Find the length and width of the rectangle.

Solution:

3) Sam is presently 7 years older than Fred. One year ago, Sam was twice as old as Fred was then. How old is each now?

person age now age 1 year ago
Fred x x 1
Sam x + 7 x + 7 1

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4) The sum of the squares of two consecutive integers is 221. Find 2 solutions for these integers.

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5) A grocer wishes to make a mixture of 80 Kg. of coffee to sell at $4.00 per Kg. He has some coffee that sells for $5.50/kg and cheaper coffee that sells for $3.00/kg. How many kilograms of each type of coffee must he put in the mixture?

item amount unit price($) value($)
$5.50 coffee x kg 5.50 5.50 x
$3.00 coffee (80 x) kg 3.00 3.00(80 x)
mixture 80kg 4.00 320x

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6) A bicycle party travels at 25 km/h. At what speed must a second bicycle party travel in order to overtake the first party in 3 hours if they start from the same place 1 hour later than the first party?

party distance rate time
early party 100 km. 25 km/h 4 hours
late party 3x km x km/h 3 hours

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