Tutors Answer Your Questions about Linear Algebra (FREE)
Question 252427: Can someone please help. I cannot figure out the correct formula.
Using a Linear System to Solve an Application. Jane Hooker invests $40,000 received in an inheritance in three parts. With one part she buys mutual funds that offer a return of 2% per year. The second part, which amounts to twice the first, is used to buy government bonds paying 2.5% a year. She puts the rest of the money into a savings account that pays 1.25% annual interest. During the first year, the total interest is $825.00. How much did she invest at each rate?
Answer: ($10,0000 at 2%; $20,000 at 2.5%; and $10,000 at 1.25%)
Click here to see answer by Theo(3464)   |
Question 252429: Principles of Counting or Permutations. What formula do I use here.
Telephone Numbers. How many 7-digit telephone numbers are possible if the first digit cannot be 0 and:
a.) Only odd digits may be used. Answer: (78,125)
b.) The telephone number must be a multiple of 10 (that is, it must end in 0). Answer:(900,000)
c.) The telephone number must be a multiple of 100. Answer:(90,000)
d.) The first 3 digits are 481. Answer:(10,000)
e.) No repetitions are allowed. Answer:(544,320)
Click here to see answer by palanisamy(496) |
Question 252428: Can someone please help. I cannot figure out the correct formula.
Using a Nonlinear System.
Modeling Circuit Gain. In electronics, cicuit gain is modeled by G = Bt/R + rt, where “R” is the value of a resister, “t” is temperature, Rt is the value of R at temperature “t”, and B is a constant. The sensitivity of the circuit to temperature is modeled by S = BR/(R + Rt)^2. If B = 3.7 and "t" is 90K (Kelvin), find the values of R and Rt that will make G = .4 and S = .001.
Answer: R= 187 , Rt = 645
Click here to see answer by Theo(3464) |
Question 252430: Please help.
Write each event in set notation and give the probability of the event. (1, 2, 3, 4, and 5)
a.) both slips are marked with even numbers.
b.) both slips are marked with odd numbers.
c.) both slips are marked with the same number.
d.) one slip is marked with odd number, the other with an even number.
Click here to see answer by drk(1908) |
Question 251271: a+b+c+d+e+f=0
a-2b=0
a+2b+3d+2e=220
1+3c+2d+2f=110
a+2b+4d+e+5f=240
a+2d+3e+4f=165
*write the equations in matrix form AX=B.
*using an appropriate software package find the inverse of A.
*solve the above equations using the Matrix Inverse Method.
*check your answer using Cramer's rule and the Gaussian Elimination Method.
Click here to see answer by Edwin McCravy(8909)  |
Question 252517: Please help. I cannot figure just what formula to use.
(Using Nonlinear Systems) Solving problems using a System of of Equation in two variables.
Unknown numbers. Find two numbers whose sum is 10 and whose squares differ by 20.
Answer( 6 and 4)
Click here to see answer by richwmiller(9143)  |
Question 252519: Can someone please point me in the right direction with this experiment. Probabilities and Binomial Experiments.
U.S. Population by Region. The U.S. population by region (in millions) for selected years is given in the table. Find the probability that a U.S. resident selected at random satisfies the following:
a.) lived in the West in 1997.
b.) lived in the Midwest in 1995.
c.) lived in the Northwest or Midwest in 1997.
d.) lived in the South or West in 1997.
e.) What are the odds that a randomly selected U.S. resident in 2000 was not from the South?
REGION 1995 1997 2000
Northwest 51.4 51.6 53.6
Midwest 61.8 62.5 64.4
South 91.8 94.2 100.2
West 57.7 59.4 63.2
(Answers) a. .222 b. .235 c. .426 d. .574 e. 302 to 167
Click here to see answer by richwmiller(9143) |
Question 252626: Can someone please assist with b and c. I cannot figure out the formula.
1. Delegation Choices. Seven workers decide to send a delegation of 2 to their supervisor to discuss their grievances.
a.) How many different delegations are possible? Answer 7 nCr 2 = 21
b.) If it is decided that a certain employee must be in the delegation, how many different delegations are possible? Answer: 6
c.) If there are 2 women and 5 men in the group, how many delegations would include at least 1 woman?
Answer: 11
Click here to see answer by drk(1908) |
Question 253409: "Plumber Greg came to fix the Brown’s sink. He worked for four hours. The bill for the Browns was $34.59. Then he fixed the Minnick’s septic tank which took him 7 hours. The total bill was $55.23."
What is the independent and dependent variable?
Click here to see answer by tushki(2) |
Question 253409: "Plumber Greg came to fix the Brown’s sink. He worked for four hours. The bill for the Browns was $34.59. Then he fixed the Minnick’s septic tank which took him 7 hours. The total bill was $55.23."
What is the independent and dependent variable?
Click here to see answer by richwmiller(9143) |
Question 254881: you are in charge of constructing a fence around the running track at a high school. the fence is to be built around the track so that there is a uniform gap between the outside edge of the track and the fence.
a. what is the maximum width of the gap between the track and the fence if no more than 630 meters of fencing is used? (hint: use the equation for teh circumference of a circle.) two sides of the track are both 100m each the other two sides are both 81m each
Click here to see answer by ankor@dixie-net.com(15652)  |
Question 255156: please just help me with these two problems I am so confused... but so happy my dad found this website!! I graphed these twice and got a line and when I did it wrong I made my own V shape on the Y axis on purpose.
Thanks!
4. y=|-3x|
40. y=-|x-3|
I have way more problems but I'm hoping if a professional shows me how to do it that well... I might understand it or get how to do this for my other problems. Thanks again!!
Click here to see answer by dabanfield(803) |
Question 255156: please just help me with these two problems I am so confused... but so happy my dad found this website!! I graphed these twice and got a line and when I did it wrong I made my own V shape on the Y axis on purpose.
Thanks!
4. y=|-3x|
40. y=-|x-3|
I have way more problems but I'm hoping if a professional shows me how to do it that well... I might understand it or get how to do this for my other problems. Thanks again!!
Click here to see answer by Edwin McCravy(8909) |
Question 243859: farmer adelita has only ducks and cows. he cant remeber how many of each he has but he doesnt need to remeber because he knows he has 22 animals and 22 is also his age. he also knows that the animals have a total of 56 legs and that is also his father age. assuming that each animal has all legs intact and no extra limbs how many of each animal does farmer ben have?
Click here to see answer by Edwin McCravy(8909) |
Question 256049: which pattern is not linear a. 1,6,11,16,21,...
b. -1,7,15,23,31,...
c. 1,21,31,41,...
d. 1,3,9,27,81,
Click here to see answer by stanbon(57352) |
Question 256059: which pattern is not linear a. 1,6,11,16,21,...
b. -1,7,15,23,31,...
c. 1,21,31,41,...
d. 1,3,9,27,81,
Click here to see answer by drk(1908) |
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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
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