Guido

Most popular questions and responses by Guido
1. Self-Taught Mathematicians

Those of us who love math certainly know two basic facts about Mr. Gottfried Wilhelm Leibniz: (1) He and Newton (our calculus guy) did not get along AND (2) Mr. Leibniz was a self-taught mathematician My question is for all tutors here who love math. What

2. Math...For All Math Tutors

I would like to know how many of the people answering math questions here are current math teachers, were math teachers at one time, are current tutors working for a tutoring company or simply love math. What's your story? I would love to hear from all

3. What Makes A Good Math Teacher?

I think a good math teacher is someone who can explain math topics at the level of students. A good math teacher is someone who does not try to impress students with his or her math skills (college math professors are famous for boasting). In your opinion,

4. Education/Subbing

How many sub teachers can really say that they are happy working as a sub teacher? Look deep inside and honestly answer the question: Are You Happy Subbing?

5. Education

I was wondering how sub teachers survive during the long summer months when there is no pay, especially if you live alone and must pay rent. If you are a sub who lives alone, what plans do you have for YOUR future, financially speaking? Do you save money

1. math

Multiply all numerators and all denominators together. Then, reduce the fraction, if needed. Multiplying numerators: 3 x 1 x 2 = 6 Multiplying denominators: 4 x 2 x 3 = 24 We now have this new single fraction: 6/24 Can we reduce this fraction? Yes, we can.

posted on February 22, 2008
2. Self-Taught Mathematicians

Reiny, Isn't it true that both men "invented" calculus independently, though Newton discovered it first? For some reason, they often argued, mathematically speaking.

posted on February 22, 2008
3. algebra

We have a fractional equation: 5/8*t + 2/15*t = 17/20 Our first goal is to find the LCD. What is the LCD of 8, 15 and 20? How about 120? Yes, LCD = 120. We now multiply each term on BOTH sides of the fractional equation by 120 to do away with ALL the

posted on February 22, 2008
4. Math

You were given: Find a number such that 32 is 60% of the number. NOTE: Decimal answer rounded to nearest tenth. Let x = number we want to find The word [of] means to MULTIPLY in math. The word [is] means EQUAL. We now have this equation: 32 = 0.60(x)

posted on February 22, 2008
5. Math

Let x = original budget Formula to use: amount spent = given percent times x \$3000 = 1.25(x) Divide both sides by 1.25 to find x. \$3000/1.25 = x \$2400 = x

posted on February 22, 2008
6. Trigonometry

I want to expand drwls' reply. First, convert 2 miles to feet. If 1 mile = 5280, then 2 miles = 10,560 feet. Secondly, you must re-arrange the given formula because we are looking for an angle NOT height or distance on ground. Let t = theta FOR SHORT.

posted on February 22, 2008
7. Math

Those are the rules for multiplication of signed numbers.

posted on February 21, 2008
8. Shapes

It is a "sector" of a circle with two radii and a small piece of the circle that we call a sector. Damon is right.

posted on February 21, 2008
9. Shapes

A half-moon-shaped.

posted on February 20, 2008
10. math

We have the decimal number: 15.35, which becomes 15(35/100). The fractional part can be reduced. What is the biggest number that can evenly fit into 35 and 100 without a remainder? How about 5? 35/5 = 7 100/5 = 20 Final answer: 5_7/20 =============== The

posted on February 20, 2008
11. MATH

Question 1: 92 - 4 = 88; y = 22 88 - 4 = 84; y = 21 84 - 4 = 80; y = 20 80 - 4 = 76; y = 19 76 - 4 = 72; y = 18 72 - 4 = 68; y = 17 What's the answer? When x = 68, y = 17. ==================== For question 2: IF Y = X-19, WHAT IS THE VALUE OF X WHEN Y= 34.

posted on February 20, 2008
12. math

s = 2 + 4 + 6 + 8 + 10 s = 30 t = 1 + 3 + 5 + 7 + 9 t = 25 Then: s - t = 30 - 25 s - t = 5 Done!

posted on February 20, 2008
13. algebra

If you think about it, 1/5 is really 5^-1, which is read "five raised to the negative one." 125 becomes 5^3. We needed to have the SAME BASE of 5 on BOTH sides of the exponential equation. We now have this: 5^-1(x - 2) = 5^3 NEXT: Remove the parentheses

posted on February 20, 2008
14. trig

We have trig identities. cscx - sinx to cotx(cos x). cscx is the reciprocal of the sine function. So, then: cscx = 1/sinx We now have: 1/sinx - sinx...Treat this like a fraction case. 1/sinx - sinx becomes (1 - sin^2x)/sinx Of course, (1 - sin^2x) is one

posted on February 20, 2008
15. Calculus?

What is ã mean????

posted on February 20, 2008
16. math

posted on February 20, 2008
17. inequality

This has nothing to do with inequalities. You are simply looking asymptotes. First of all, what is an asymptote? You need to know the definition of math terms. An asymptote is a boundary line that a graph gets very, very, very close to but NEVER (say

posted on February 20, 2008
18. inequalities

bobpursley, How can you factor x^2 + 9 into (x - 3) (x + 3) when there is a PLUS sign between x^2 and the constant 9? Get my point?

posted on February 20, 2008
19. algebra

Kay, I think Mel is looking for an answer in a different base system. Mel, what base are you talking about? If you are takling about base 10? If so, then the answer is 2. OR... Are you talking about base 3, base 4, base 5, which one?

posted on February 20, 2008
20. algerbra

We have this: 10^7 * 10^3 ------------- = 10^4 * 10^-9 We can multiply the numerators and denominators as step one, if you'd like. 10^7 * 10^3 = 10^10 = our numerator. 10^4 * 10^-9 = 10^-5 = our denominator. We now have this fraction: 10^10/10^-5 Since we

posted on February 20, 2008
21. Algebra

I want to say what Damon said in a different way. In the y-intercept equation y = mx + b (an equation that represents linear functions), the domain is ALL REAL NUMBERS going from negative infinity to positive infinity; the range is also ALL REAL NUMBERS y.

posted on February 20, 2008
22. Math

We have composite functions here. You are given: If g(x)= 3x-8, find g[g(-4)]. By the way, g[g(-4)] can also be written g(g(-4)) and it's read: "g of g of negative four." We are looking for g of g of x first. To do so, replace x in (3x - 8) with the value

posted on February 20, 2008
23. Math

3b. Pick any two points on the line and find the slope of the line. The slope is a numerical value that describes just how slanted a given line is. Here is is an example of finding the slope of a line. SAMPLE: Given the points (3, 4) and (8, 9), find the

posted on February 20, 2008
24. Pre-Algebra

3a. The y-intercept is found when you set x to = 0. The y-intercept is the point where the graph of the line crosses the y-axis. SAMPLE: In the equation y = 3x + 5, what is the y-intercept? It is the point (0,5). Do you see number 5? That number represents

posted on February 20, 2008
25. Math

Do what I said. Use the quadratic formula or completing the square. You can search the net for many math sites that easily teach you about the quadratic formula and/or completing the square.

posted on February 19, 2008
26. nystce exam

Go to your local public library. They have the guides plus plenty of material that will help you prepare for the exams. I took the LAST in April 2001 and scored very high on it. You can also go to the UFT. They offer training courses for a reasonable fee

posted on February 19, 2008
27. math

Multiply: 248 times 63 = 15,624

posted on February 19, 2008
28. Math

Okay, you want to factor this equation, right? We have this: y^2 - 4y - 2 = 0 You can use the quadratic formula or completing the square to solve this question.

posted on February 19, 2008
29. algebra 1

We have: sqrt{60} = We have to break the radicand down (our 60). What two numbers (one of them must be a perfect square) multiplied together will produce 60? How about sqrt{4} times sqrt{15}? Yes, sqrt{4} times sqrt{15} = sqrt{60} and the sqrt{4} is a

posted on February 19, 2008
30. Math

posted on February 19, 2008
31. Math

We have a quadratic equation here. Do you want to factor this equation? What exactly do you want to do with this equation?

posted on February 19, 2008
32. math

If that is the case, then this should be a new question and thus a new topic.

posted on February 19, 2008
33. Pre Cal

We use sine = opp/hyp Let x be the height of the slope that we are seeking. sin(25.2 degrees) = 1808 feet/x Multiply both sides by x and we get: sin(25.2 degrees)(x) = 1808 feet Next: Divide both sides by sin(25.2 degrees) to find x. x = 1808 feet/sin(25.2

posted on February 19, 2008

x + 4 (x + 3) This is not a FOIL situation. You must first clear the parentheses. 4 times x = 4x 4 times 3 = 12 We now have: x + 4x + 12 Combine like terms is our next step. x + 4x = 5x Final answer: 5x + 12 Done!

posted on February 19, 2008
35. math

You have to tell us what 31.4cm represents. Does it represent the radiu or diameter? Which one? 78.5 squared means to multiply 78.5 by itself. 78.5 x 78.5 = 6162.25 What does 6162.25 have to do with 31.4cm? Please, clarify your question.

posted on February 19, 2008
36. MATH

Do you have a sample question?

posted on February 19, 2008
37. Math

Use the factor tree method to solve both questions.

posted on February 19, 2008
38. math

Do you have sample questions?

posted on February 19, 2008
39. basic math

Do you have a question for me?

posted on February 19, 2008
40. Math

87 x 86 x 85 x 84 x 83 = ???

posted on February 19, 2008
41. math

This is not a math question.

posted on February 19, 2008
42. math

What is spens? This is not a math question.

posted on February 19, 2008
43. Geometry

Graph all the points given on the xy-plane. If you get a picture of a KITE, then the answer is yes. Of course, I graphed all the points for you and determined that the given 4 points form a picture of a kite. Done!

posted on February 18, 2008
44. Algebra

Can I break what down step by step?

posted on February 18, 2008
45. pre-algebra

Damon, I got the same answers except I replied using fractions.

posted on February 18, 2008
46. pre-algebra

Here is some information for you: There are 86,400 seconds in one day. There are 3 feet in one yard = 36 inches in one yard. 3/86,400 = 1/28,800 days. 2/36 = 1/18 inches. Is this what you wanted?

posted on February 18, 2008
47. Math

Mike, After doing the question again, I realize that 4x - x^2 is not one-to-one. Hence, it has no inverse function. Sorry....The answer is: NO INVERSE FUNCTION HERE.

posted on February 18, 2008
48. math :]

posted on February 18, 2008
49. Math

A rational number is a number that can be written as a fraction. 14/3 is an improper fraction and thus rational.

posted on February 18, 2008
50. Algebra

Yes, you can. Here is a sample literal equation. Solve for h. h + rt = j Subtract rt from both sides to find h. h = j - rt Done! I just solved for h, which is a variable. Solving for variables is very common in the world of algebra.

posted on February 18, 2008
51. Algebra

An equation has an EQUAL ( = ) sign; an expression does not. Sample Equation: 3x + 5 = 10 Sample Expression: 30x + 40y See the difference?

posted on February 18, 2008
52. math

First, find the circumference of the circle with diameter 5 feet. We use this formula: C = pi x d, where pi = 3.14 and d = 5 feet C = 3.14 x 5 feet C = 15.7 feet Now multiply 15.7 feet by \$3 and you will find how much it will cost to have the top

posted on February 18, 2008
53. pre-algebra

Is there a typo here? You meant 3 seconds? There are 24 hours in one day. 60 minutes = 1 hour. 60 seconds = 1 minute. How many minutes in one day? 60 x 24 = 1440 minutes in one day. How many seconds in one day? 1440 x 60 = 86,400 seconds in one day. How

posted on February 18, 2008
54. math

Find the area of the given triangle as step 1. A = 1/2(base)(height)....This is the general formula used to find the area of a triangle when base and height are given. A = 1/2(30)(20) A = 1/2(600) A = 300 square feet The front will cost \$3 per square feet

posted on February 18, 2008
55. Math

You were given: y = 4x - x^2 We switch x and y. x = 4y - y^2 Factor the right side of the equation. x = y(4 - y) Next: xy = 4 - y Add y on both sides of the equation. xy + y = 4 Factor on the left side. y(x + 1) = 4 Isolate y on the left side. y = 4/(x +

posted on February 18, 2008
56. pre- algebra

new price = \$30 The new price (or \$30) = 3x - 6 old price = x We now equate: 30 = 3x - 6 30 + 6 = 3x 36 = 3x 36/3 = x 12 = x Old Price = \$12. Done!

posted on February 17, 2008
57. math

Yes, you are right.

posted on February 17, 2008
58. pre- algebra

Joshua did a great job! I just want to say that to solve for a variable (any variable) means to isolate the variable on one side of the equation. Do you see, as Joshua said, that t = 13? Do you see that the letter or variable t has been isolated on one

posted on February 17, 2008
59. math

48/60 = x/300 We now cross-multiply. 60(x) = 48(300) 60x = 14,400 x = 14,400/60 x = 240 So, what is the fraction? 240/300 What does 240/300 really mean? It means that if we were to reduce it to the lowest term, we would end up with 48/60. Why? Because they

posted on February 17, 2008
60. Algebra

We have this: (y -< x + 2) = point 1. (x + 2 -< 6) = point 2. (y >- -2) = point 3. Replace all inequality symbols with an equal sign for easy simplification. Point 3: y >- -2 becomes y = -2 We just found y. We plug y = -2 in point 1 to find x. -2 = x + 2

posted on February 17, 2008
61. Algebra

The way you typed your questions is not clear. Please use proper keyboard symbols.

posted on February 17, 2008
62. Algebra II

Well-done!

posted on February 17, 2008
63. Math

Well, 16 feet = 192 inches. 13_3/8 x 12 = 160_1/2 inches. 192 inches - 160_1/2 inches = 31_1/2 inches. You can also write it as 31.5 inches. You forgot the 1/2. Other than that, good job!

posted on February 17, 2008
64. algbra

I guess you meant to type: y^-5 times y^-10. Well, y^-5 becomes 1/y^5. Also, y^-10 becomes 1/y^10. We now have this: (1/y^5) times (1/y^10) = 1/y^15

posted on February 17, 2008
65. math

Sue = 1/45 Bill = 1/65 Together = 1/x 1/45 + 1/65 = 1/x We have a fractional equation. Solve for x. What is the LCD of 45, 65 and x? It 585x. We now multiply every term on BOTH sides of the fractional equation by the LCD. (1/45)(585x) + (1/65)(585x) =

posted on February 17, 2008
66. algebra

You can only add or subtract two polynomial terms together if they have the same variables; terms with matching variables are called "like terms." Radicals work in a very similar way. Sample radical expression: 3(sqrt{2xy}) - 2(sqrt{50xy})

posted on February 17, 2008
67. calculace

First of all, it is spelled calculus. Next, show your work so that we know where you need help. Okay?

posted on February 17, 2008
68. algebra

In order to to add or subtract radicals together, they must be like radicals; in other words, they must have the EXACT same radicand and index. This is the main reason why we must simplify them. If you are asked to add or subtract radicals that have

posted on February 17, 2008
69. math

We have a fractional equation. Your first goal should be to do away with the fractions. It is easier to work with equations that have no fractions. What is the LCD of 21 and 49? Reiny said 147. 147/21 = 7 147/49 = 3 Yes, 147 = LCD. We multiply each term on

posted on February 17, 2008
70. math

Formula needed is: A = 1/2(base)(height) 44 = 1/2(x + 3)(x) One leg is 3m longer than the other can be expressed as (x + 3). The other leg is simply the letter (x). In other words, (x + 3) is one of the legs and the letter (x) is the other leg. This is

posted on February 17, 2008
71. maths

Good point and you are right. I did not capture that part of the question. Good looking out, Reiny. Thanks for the correction.

posted on February 17, 2008
72. calculace

First of all, it is spelled calculus. Next, show your work so that we know where you need help. Okay?

posted on February 17, 2008
73. maths

The word half = 1/2. Four fifths = 4/5. To find the answer, we subtract 1/2 from 4/5. Now: 1/2 = 50 4/5 = 80 80 - 50 = 30 30 = 3/10 Done!

posted on February 17, 2008
74. Algebra

I will do number one only. We have this: (1)Find x in the solution of the system 3x + y = 2 and 2x -3y = 16. (A)2 (B)-4 (C)18/11 (D)10/11 Your choice = (A) We have a system of linear equations in two variables. Here are the two equations: 3x + y =

posted on February 17, 2008
75. math probabilty

This question is incomplete.

posted on February 17, 2008
76. maths

We have: I am a three digit number. My tens digit is twice my ones digit, my hundreds digit is twice my tens digit. I am greater than 500. Who am I? How about 631? 631 is > 500. This is a math riddle not a math question. There are several answers.

posted on February 17, 2008
77. geometry

What is your geometry question? What exactly do you need help with in terms of geometry? Write back....

posted on February 16, 2008

The solutions are found at the location (x ,0), where x represents any value and 0 represents the y coordinate. Three samples: (4, 0), (-6, 0) and (-1/2, 0)

posted on February 16, 2008
79. math

To pick up on what drwls said, in terms of prime factorization, we can also write the example given using exponents. The prime factorization of 120 = 5 x 3 x 2^3, where 2 is raised to the third power.

posted on February 16, 2008
80. Math

This question does not make sense. What are the instructions? What do you want to do with your fraction?

posted on February 16, 2008
81. algebra

What is the slope of the line? The slope of a line is equal to the following fraction: (number of vertical units it takes to travel from one point to another)/(number of horizontal units it takes to travel from one point to another. The letter m has been

posted on February 16, 2008
82. Math

Babygirl, You have the same question as babygirl. Does Bybygirl = Tim and vice-versa? To find the final exam score, add all the scores and then divide by the number of scores listed, which is 15. ============================== Median is the middle value of

posted on February 15, 2008
83. Math

Ms. Sue knows that Tim = babygirl, right?

posted on February 15, 2008
84. Math

Tim, You have the same question as babygirl. Does Tim = babygirl and vice-versa? To find the final exam score, add all the scores and then divide by the number of scores listed, which is 15. ============================== Median is the middle value of a

posted on February 15, 2008
85. Math...For All Math Tutors

Very interesting reply. I wish your son the best in the world. He is a very smart and will always be successful. Math can either break you and make you. It depends on the person and the choices we make. It's sad to know that colleges don't tell the truth

posted on February 15, 2008
86. Trig

Good job Reiny. Guido

posted on February 15, 2008
87. Right triangle

The easiest way is to use the distance formula for points in the (x,y) form. Use the formula 3 times. You have triangle GHJ. Use the formula from point: G to H H to J G to J Only then will you be able to tell if triangle GHJ is a right triangle or not.

posted on February 15, 2008
88. Mth finding modes

Again, the mode is a number that appears more than the rest on a given list. There is no mode in your list because each number appears JUST ONE time. Get it?

posted on February 15, 2008
89. math

The Mean is the average. 1-We add the number of miles driven. 238 + 159 + 87 + 163 + 198 = 845 2-We now divide 845 by 5. 845/5 = Mean 169 miles = Mean Done!

posted on February 15, 2008
90. Math find the mode

The mode is the number that is listed the most. You can see that 9 appears more than the rest of the numbers. Then, 9 is the mode.

posted on February 15, 2008
91. Algebra

This question is incomplete.

posted on February 15, 2008
92. algebra

What equation? Where is the equation?

posted on February 15, 2008
93. trigonomitry

Use a trig function that states opposite/hypotenuse. Of course, this would be the sine function. sin(45degrees) = h/7meters Let h = height of building sin45 = h/7 sin45 times 7 = h 4.949747468 = h Round 4.949747468 to the nearest tenths becomes 4.95

posted on February 15, 2008
94. Algebra

Here it is: First multiply 7 x 1/2 = 7/2. We now have this equation: 42 = 7/2(b1) + 9) Simplify the right side of the equation and the whole thing becomes 42 = 7/2(b1) + 63/2 Subtract 63/2 from 42. 42 - 63/2 = 10_1/2 We now have: 10_1/2 = 7/2(b1) 10_1/2

posted on February 15, 2008
95. Algebra

I will set it up for you and you can simplify. A = 42 h = 7 b2 = 9 I will plug and you can chug. 42 = 1/2(b1 + 9)(7) Solve for b1, which is read "b sub one." Can you take it from here?

posted on February 15, 2008