Tutors Answer Your Questions about Systems-of-equations (FREE)
Question 1113419: 1.Explain how you can determine if a system of equations will have no solution when comparing the graph of the equations.
2.Explain how you can determine if a system of equations has no solution by comparing each algebraic equation.
Click here to see answer by amalm06(224)   |
Question 1113419: 1.Explain how you can determine if a system of equations will have no solution when comparing the graph of the equations.
2.Explain how you can determine if a system of equations has no solution by comparing each algebraic equation.
Click here to see answer by ikleyn(52775)  |
Question 1113181: The function 4.3x+y=198 models the number of land-line phone customers, in millions, x years after 2000. The function y=19.8x+98 models the number of cell phone customers, in millions, x years after 2000.
a. Use these models to determine the year, rounded to nearest year, when the number of cell phone and landline customers is the same.
b. according to the models, how many customers were there for each type of phone customer for the year determined in part a. (rounded to the nearest ten million)?
Click here to see answer by Theo(13342)  |
Question 1113747: Sam invested $1950, part of it at 6% and the rest at 8% yearly interest. The yearly income on the 8% investment was $26 more than twice the income from the 6% investment. How much did he invest at each rate?
Click here to see answer by ikleyn(52775) |
Question 1113964: Solve the linear programming problem by using the graphing method illustrated in this example.
A manufacturer of golf clubs makes a profit of $55 per set on a model A set and $45 per set on a model B set. Daily production of the model A clubs is between 30 and 50 sets, inclusive, and that of the model B clubs is between 20 and 20 sets, inclusive. The total daily production is not to exceed 50 sets. How many sets of each model should be manufactured per day to maximize the profit?
Click here to see answer by ikleyn(52775) |
Question 1114053: twenty percent of a salary is spent on food. 2x that amount is spent on a house payment and 1/2 the amount spent on food is spent on utilities. these three amounts total to $1050. what is the amount of the monthly salary?
Click here to see answer by amalm06(224) |
Question 1114280: A manufacturer of small copiers makes a profit of $200 on a deluxe model and $250 on a standard model. The company wants to produce at least 70 deluxe models per week and at least 55 standard models per week. However, the weekly production is not to exceed 160 copiers. How many copiers of each kind should be produced in order to maximize the profit?
Click here to see answer by greenestamps(13198)  |
Question 1114278: The income from a student production was $21,500. The price of a student ticket was $4, and nonstudent tickets were sold at $7 each. Five thousand tickets were sold. How many tickets of each kind were sold?
Click here to see answer by ikleyn(52775) |
Question 1115282: Hello! I have a word problem that I need help solving.
My problem : Two hikers are walking along a marked trail. The first hiker starts at a point 6 miles from the beginning of the trail and walks at a speed of 3mph. At the same time, the second hiker starts 1 mile from the beginning and walks at a speed of 4mph. When will they be at the same point on the trail?
I have trouble trying to find a way to solve it using substitution and elimination. I have tried but I can't seem to find the correct way to do it. I would appreciate any help, thank you!
Click here to see answer by mananth(16946)  |
Question 1115282: Hello! I have a word problem that I need help solving.
My problem : Two hikers are walking along a marked trail. The first hiker starts at a point 6 miles from the beginning of the trail and walks at a speed of 3mph. At the same time, the second hiker starts 1 mile from the beginning and walks at a speed of 4mph. When will they be at the same point on the trail?
I have trouble trying to find a way to solve it using substitution and elimination. I have tried but I can't seem to find the correct way to do it. I would appreciate any help, thank you!
Click here to see answer by josgarithmetic(39616) |
Question 1115646: At a college play production, 360 tickets were sold. The ticket prices were $8, $10, and $12 and the total income from ticket sales was 3436. How many tickets of each type were wold if the number of $8 tickets sold was twice the number of $12 tickets sold?
Click here to see answer by josgarithmetic(39616) |
Question 1115646: At a college play production, 360 tickets were sold. The ticket prices were $8, $10, and $12 and the total income from ticket sales was 3436. How many tickets of each type were wold if the number of $8 tickets sold was twice the number of $12 tickets sold?
Click here to see answer by ikleyn(52775) |
Question 1115647: A coffee manufacturer sells a 10-pound package of coffee that consists of three flavors of coffee. Vanilla-flavored coffee costs $12 per pound, hazelnut-flavored coffee costs $13.50 per pound, and mocha-flavored coffee costs $15 per pound. The cost of the 10 pound package is $138. The package contains the same amount of hazelnut coffee as mocha coffee. How many pounds of each type of coffee are in the package?
Click here to see answer by josgarithmetic(39616) |
Question 1115647: A coffee manufacturer sells a 10-pound package of coffee that consists of three flavors of coffee. Vanilla-flavored coffee costs $12 per pound, hazelnut-flavored coffee costs $13.50 per pound, and mocha-flavored coffee costs $15 per pound. The cost of the 10 pound package is $138. The package contains the same amount of hazelnut coffee as mocha coffee. How many pounds of each type of coffee are in the package?
Click here to see answer by ikleyn(52775) |
Question 1116032: create two scenarios of your own that involve relations in real life. Describe the scenarios in
detail, including a description of the two variables involved and data for each of the variables.
Then create either a table, a mapping diagram, or a graph to represent the data in each scenario.
Include at least three data points in your representation. Use a different way to represent the
relation for each of your scenarios.
Click here to see answer by josgarithmetic(39616) |
Question 1116932: Given that the energy(e) varies directly as the resistance(r) and inversely as the square of the distance(d) if e=32/25, r=8 and d=5
a) calculate the constant k
b) calculate r when e=16 and d=3
c) calculate d when r=5 and e=5/6
Click here to see answer by solver91311(24713)  |
Question 1116932: Given that the energy(e) varies directly as the resistance(r) and inversely as the square of the distance(d) if e=32/25, r=8 and d=5
a) calculate the constant k
b) calculate r when e=16 and d=3
c) calculate d when r=5 and e=5/6
Click here to see answer by KMST(5328)  |
Question 1116932: Given that the energy(e) varies directly as the resistance(r) and inversely as the square of the distance(d) if e=32/25, r=8 and d=5
a) calculate the constant k
b) calculate r when e=16 and d=3
c) calculate d when r=5 and e=5/6
Click here to see answer by MathTherapy(10551)  |
Question 1117955: Two Ferris wheels are side-by-side are rotating at the Math Fair. The first Ferris wheel has a radius of 7m and makes one complete revolution every 16 s. The bottom of the wheel is 1.5 m above ground. The second Ferris has a radius of 8m and completes one revolution every 20 s. The bottom of this wheel is 2 m above the ground. What are the equations of both Ferris wheels using sine as the base function
Click here to see answer by Alan3354(69443)  |
Question 1118285: It is a beautiful sunny day at the fair. The U.V. index for this day is 8, or high, so sunscreen is a must for all the young folk. The effectiveness of sunscreen is indicated by the sunscreen protection factor (SPF). The higher the SPF number the fewer U.V. rays can penetrate to burn the skin. When the protection factor (SPF), s, is known you can determine the percent, p, of the sun’s ultraviolet rays that pass through it by using the following mathematical model:
[Marks: a: 2; b: 3; c: 3]
P=1000/s
a. What are the asymptotes for this function? Interpret the meaning of the asymptotes based on the scope of the problem.
b. Graph the function.
c. The sunbathers on the beach were using a sunscreen with SPF of 35. What percent of the sun’s rays will pass through to skin?
All parts please
Click here to see answer by Boreal(15235)  |
Question 1118284: The amusement park has a Ferris wheel with a radius of 4 m and it takes 1 minute to make one revolution. The lowest carriage is 1 m above the ground. Consider the height of a specific carriage as the wheel rotates:
[Marks: a: 2; b: 2; c: 5; d: 3]
a. What are the independent and dependent variables?
b. Construct a table of values.
c. What is the mathematical model for this situation?
d. Graph the function.
Please do all parts
Click here to see answer by Alan3354(69443) |
Question 1118286: KMST NOTE:
I removed the unneeded space.
The young folk decide to ride the Terror Tower (the Chaperones opt to watch from the comfort of the ground!). At its maximum height, the ride reaches 65 m above the ground. When one boy reaches the top of the tower, his gum falls out of his mouth. The height of the gum can be given by the mathematical model:
h=65-4.9t^2, where t is in seconds and h is measured in metres.
[Marks: a: 4; b: 6]
a. Find the average velocity of the gum on the intervals 2 <_ t <_3 and 2 <_ t <_2.1
b. Find the instantaneous velocity when t=2.
all questions please
Click here to see answer by Alan3354(69443) |
Question 1118286: KMST NOTE:
I removed the unneeded space.
The young folk decide to ride the Terror Tower (the Chaperones opt to watch from the comfort of the ground!). At its maximum height, the ride reaches 65 m above the ground. When one boy reaches the top of the tower, his gum falls out of his mouth. The height of the gum can be given by the mathematical model:
h=65-4.9t^2, where t is in seconds and h is measured in metres.
[Marks: a: 4; b: 6]
a. Find the average velocity of the gum on the intervals 2 <_ t <_3 and 2 <_ t <_2.1
b. Find the instantaneous velocity when t=2.
all questions please
Click here to see answer by josgarithmetic(39616) |
Question 1118286: KMST NOTE:
I removed the unneeded space.
The young folk decide to ride the Terror Tower (the Chaperones opt to watch from the comfort of the ground!). At its maximum height, the ride reaches 65 m above the ground. When one boy reaches the top of the tower, his gum falls out of his mouth. The height of the gum can be given by the mathematical model:
h=65-4.9t^2, where t is in seconds and h is measured in metres.
[Marks: a: 4; b: 6]
a. Find the average velocity of the gum on the intervals 2 <_ t <_3 and 2 <_ t <_2.1
b. Find the instantaneous velocity when t=2.
all questions please
Click here to see answer by KMST(5328) |
Question 1117276: Hey there,
I’m not sure if this is the correct category for this question, but I’m not sure where else to post it. Also, this is not technically a homework question, but a question for a personal project I have been working on.
Some background: I am trying to predict the score of MLB baseball games before they occur using team statistics. Right now, to predict the score for a given team, I multiply four “factors” together. The factors are:
1. MLB Average Team Runs Per Game (typically around 4.5)
2. Team’s Hitting Score (a score I give to this team to tell me how much better or worse than average they are at hitting – typically ranges from 0.8 to 1.2)
3. Opponent’s Pitching Score (a score I give to this team’s opponent based on how good or bad their starting pitching and bullpen pitching is – typically ranges from 0.6 to 1.4)
4. Park Factor (how many runs are scored at the ballpark they are playing at compared to the average park – typically ranges from 0.8 to 1.3)
It’s important to note that the hitting score, pitching score, and park factor are all “normalized” to 1.00, meaning the most average team with the most average pitcher at the most average ballpark would have 1.00 for each of those scores. A team that hits 20% worse than average would have a score of 0.8, etc.
For example, I will take today’s Atlanta Braves vs Chicago Cubs projections to show you how this is done.
For Atlanta’s Score Projection:
MLB Average Runs Per Game: 4.46
Hitting Score: 1.20 (about 20% better than the average team)
Opponent Pitching Score: 1.15 (their opponent – Cubs – are pitching about 15% worse than the average team)
Park Factor: 0.98 (2% less runs are scored at this ballpark than the average park)
When I multiply these four factors together, I get (4.46 x 1.20 x 1.15 x 0.98) which comes out to a projection of 6.03 runs scored. I have an excel spreadsheet that is tracks all of these factors, projections, and the number of runs that the team actually scored. My question for you is, how can I improve this formula that I am using for more accurate projections? Currently, this assumes that the four factors I am using are equally predictive. Basically, my formula looks like this:
Factor1 * Factor2 * Factor3 * Factor4 = ScoreProjection
However, I feel like there should be a coefficient for each factor. Maybe the team’s hitting score is not as predictive as their opponent’s pitching score, so I would need the pitching score to be more heavily weighted in my projections. So, I think I need a formula like this:
(X1*Factor1)*(X2*Factor2)*(X3*Factor3)*(X4*Factor4) = ScoreProjection
Where X1, X2, X3, and X4 are my factor coefficients. How can I go about finding these using my data that I have collected? There are obviously no perfect coefficients that would give me perfect score projections every time, so I suppose there is no true “solution” to this problem. I have investigated “multiple regression” through machine learning, but this does not yield the results I would like. Multiple regression gives me a formula like:
(X1*Factor1)+(X2*Factor2)+(X3*Factor3)+(X4*Factor4) = ScoreProjection
Where the factors are being added together as opposed to multiplied like I want. Really, I think I want to know which coefficients would lead me to the most accurate score projection (best fit line?). If this can be done, please let me know how!
Let me know of any questions that you might have. I appreciate the help!!
Barrett Gray
BarrettGray11@Yahoo.Com
Click here to see answer by ikleyn(52775) |
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Older solutions: 1..45, 46..90, 91..135, 136..180, 181..225, 226..270, 271..315, 316..360, 361..405, 406..450, 451..495, 496..540, 541..585, 586..630, 631..675, 676..720, 721..765, 766..810, 811..855, 856..900, 901..945, 946..990, 991..1035, 1036..1080, 1081..1125, 1126..1170, 1171..1215, 1216..1260, 1261..1305, 1306..1350, 1351..1395, 1396..1440, 1441..1485, 1486..1530, 1531..1575, 1576..1620, 1621..1665, 1666..1710, 1711..1755, 1756..1800, 1801..1845, 1846..1890, 1891..1935, 1936..1980, 1981..2025, 2026..2070, 2071..2115, 2116..2160, 2161..2205, 2206..2250, 2251..2295, 2296..2340, 2341..2385, 2386..2430, 2431..2475, 2476..2520, 2521..2565, 2566..2610, 2611..2655, 2656..2700, 2701..2745, 2746..2790, 2791..2835, 2836..2880, 2881..2925, 2926..2970, 2971..3015, 3016..3060, 3061..3105, 3106..3150, 3151..3195, 3196..3240, 3241..3285, 3286..3330, 3331..3375, 3376..3420, 3421..3465, 3466..3510, 3511..3555, 3556..3600, 3601..3645, 3646..3690, 3691..3735, 3736..3780, 3781..3825, 3826..3870, 3871..3915, 3916..3960, 3961..4005, 4006..4050, 4051..4095, 4096..4140, 4141..4185, 4186..4230, 4231..4275, 4276..4320, 4321..4365, 4366..4410, 4411..4455, 4456..4500, 4501..4545, 4546..4590, 4591..4635, 4636..4680, 4681..4725, 4726..4770, 4771..4815, 4816..4860, 4861..4905, 4906..4950, 4951..4995, 4996..5040, 5041..5085, 5086..5130, 5131..5175, 5176..5220, 5221..5265, 5266..5310, 5311..5355, 5356..5400
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