College Algebra
Math 110
Module 4 Writing Assignment: Midterm Exam
Grading Criteria: Your assignment will be graded according to the answer key. Show
all of your work; you may be able to earn partial credit for your thought process even
if a computational error led you to the wrong answer.
1. Find the LCM of 20 and 44.
Ans:
20 = 2 x 2 x 5
44 = 2 x 2 x 11
LCM = 2 x 2 x 5 x 11 = 220
2. Divide and simplify the following:
Ans:
24 16 24 55 15
= x =
22 55 22 16 4
3. Simplify the following:
Ans:
7 6 9 14 - 36 + 27 49
- + = =
15 5 10 30 30
4. Solve for w:
Ans:
w w
+ =28 which implies 3w + 4w =28
4 3 12
7w
Which implies =28
12
Which implies 7w = 28 x 12
, 28 x12
Which implies w = = 48
7
5. Solve the following for x: -6x+5.4=63+1.2x
Ans:
-6x + 5.4 = 63 + 1.2x which implies -6x – 1.2x = 63 – 5.4 = 57.6
Which implies that -7.2x = 57.6
- 57.6
x= = -8
7.2
6. Simplify the following, combining like terms: 2a-4(a+b)-(a-2b)
Ans:
2a – 4(a + b) – (a – 2b) = 2a – 4a – 4b – a + 2b = -3a – 2b = -(3a + 2b)
7. Simplify the following, combining like terms: {2[-4(x-y)+5]-(9x-y)}-[-2(y+3x)]
Ans:
{2[-4(x-y)+5]-(9x-y)}-[-2(y+3x)] = {2{-4x + 4y + 5] – (9x – y)} – [-2y – 6x]
= {-8x + 8y + 10 – 9x + y} – [-2y – 6x]
= -17x + 9y + 10 +2y + 6x = -11x +11y + 10
8. Simplify the following, combining like terms:
Ans:
= 5w5 – 10w4 + 45w3 – 4w3 + 8w2 – 36w
= 5w5 – 10w4 + 41w3 + 8w2 – 36w
9. Simplify the following:
Ans:
= 19 + 81 – 6 – (9 + 81 – 54)
= 19 + 81 – 6 – 9 – 81 + 54 = 58
10. Determine whether the ordered pair (-7,8) is a solution to: 8x+y = 64
Ans:
If possible, (-7, 8) is a solution to -8x + y = 64.’
Then, -8 x -7 + 8 = -56 + 8 = -48 which is not equal to 64. Hence it can be concluded
that (-7, 8) is not a solution to -8x + y = 64.
Math 110
Module 4 Writing Assignment: Midterm Exam
Grading Criteria: Your assignment will be graded according to the answer key. Show
all of your work; you may be able to earn partial credit for your thought process even
if a computational error led you to the wrong answer.
1. Find the LCM of 20 and 44.
Ans:
20 = 2 x 2 x 5
44 = 2 x 2 x 11
LCM = 2 x 2 x 5 x 11 = 220
2. Divide and simplify the following:
Ans:
24 16 24 55 15
= x =
22 55 22 16 4
3. Simplify the following:
Ans:
7 6 9 14 - 36 + 27 49
- + = =
15 5 10 30 30
4. Solve for w:
Ans:
w w
+ =28 which implies 3w + 4w =28
4 3 12
7w
Which implies =28
12
Which implies 7w = 28 x 12
, 28 x12
Which implies w = = 48
7
5. Solve the following for x: -6x+5.4=63+1.2x
Ans:
-6x + 5.4 = 63 + 1.2x which implies -6x – 1.2x = 63 – 5.4 = 57.6
Which implies that -7.2x = 57.6
- 57.6
x= = -8
7.2
6. Simplify the following, combining like terms: 2a-4(a+b)-(a-2b)
Ans:
2a – 4(a + b) – (a – 2b) = 2a – 4a – 4b – a + 2b = -3a – 2b = -(3a + 2b)
7. Simplify the following, combining like terms: {2[-4(x-y)+5]-(9x-y)}-[-2(y+3x)]
Ans:
{2[-4(x-y)+5]-(9x-y)}-[-2(y+3x)] = {2{-4x + 4y + 5] – (9x – y)} – [-2y – 6x]
= {-8x + 8y + 10 – 9x + y} – [-2y – 6x]
= -17x + 9y + 10 +2y + 6x = -11x +11y + 10
8. Simplify the following, combining like terms:
Ans:
= 5w5 – 10w4 + 45w3 – 4w3 + 8w2 – 36w
= 5w5 – 10w4 + 41w3 + 8w2 – 36w
9. Simplify the following:
Ans:
= 19 + 81 – 6 – (9 + 81 – 54)
= 19 + 81 – 6 – 9 – 81 + 54 = 58
10. Determine whether the ordered pair (-7,8) is a solution to: 8x+y = 64
Ans:
If possible, (-7, 8) is a solution to -8x + y = 64.’
Then, -8 x -7 + 8 = -56 + 8 = -48 which is not equal to 64. Hence it can be concluded
that (-7, 8) is not a solution to -8x + y = 64.