Questions on Algebra: Linear Algebra (NOT Linear Equations) answered by real tutors!

Tutors Answer Your Questions about Linear Algebra (FREE)

Question 62943:
Click here to see answer by funmath(2933)

Question 62946: The following table shows data for the city K that consist of i ts population during the time period from the year 1942 to the year 2002.
Scatter plotting
1940- 20,360
1950- 23,390
1960- 28,580
1970- 35,425
1980- 45,260
1990- 54,320
2000- 63,525
Find a qudratic model for the data.Round the values of a,b,and c to three significant digits?
Click here to see answer by stanbon(75887)

Question 63391: Please give me the workings of x^2-x-6/2x^2-13x+21
Click here to see answer by ankor@dixie-net.com(22740)

Question 63918: with a tail wind, a helicopter traveled 300mi in an hour and 40 min. the return trip aganst the same wind took 20 min longer. find the wind speed and also the air speed of the helicopter.
Click here to see answer by funmath(2933)

Question 63991: I tried this problem and did not understand my answer. i would put in my work but some of the terms i need like a fraction line are not on my computer
.5(6-z)=z
Click here to see answer by sarahschober(35)

Question 64548: Solve. Approximate to four decimal places.
4^(3x+2)=9
Click here to see answer by ankor@dixie-net.com(22740)

Question 64551: Find the midpoint of the line segment between (-3,-4) and (6,-8)
Click here to see answer by stanbon(75887)

Question 64547: ((3x^2-12)/(x^2=2x-8)) / ((6x+18)/(x=4))
Click here to see answer by stanbon(75887)

Question 64552: Solve for x: [6x-5]-3=-2
Click here to see answer by checkley71(8403)

Question 64546: (5a-2)^2-a=0
Click here to see answer by checkley71(8403)

Question 64875: write an equation in slope intercept form for the line passing through each pair of points
1. (-1,3) and (2,-5)

Click here to see answer by Edwin McCravy(20054)

Question 64945: Bette�s Bananas delivers fresh bananas to your doorstep every morning. The cost for the service is $12/month flat rate and your first ten bananas are free! Further bananas cost $0.10 each. Construct a piecewise-linear function for the cost C of receiving N bananas in a month.
Click here to see answer by stanbon(75887)

Question 65314: 2x+3y=1
-3x+4y=-10
Click here to see answer by checkley71(8403)

Question 65068: how do you graph
4x>12
2y<6
Click here to see answer by checkley71(8403)

Question 64665: What is the Graphical Method?
Click here to see answer by checkley71(8403)

Question 64649: Can anyone give me a hand with this one? Thanks!
3^x-1 = 2
Give answer to four decimal places. Thanks again!
Click here to see answer by Earlsdon(6294)

Question 65750: determine the ratio in which the line joining (0,7) and (-2,1)is
divided by the line 2x+y-4=0
Click here to see answer by Nate(3500)

Question 65750: determine the ratio in which the line joining (0,7) and (-2,1)is
divided by the line 2x+y-4=0
Click here to see answer by Edwin McCravy(20054)

Question 65751: if A(x,y) is equidistance from P(-3,2)and Q(2,-3), show that x =y
Click here to see answer by venugopalramana(3286)

Question 65749: the line joining A(2,3) and B(6,-5)meet the xaxis at P .
write down the y cordinate of P hence find the ratio AP:PB
Click here to see answer by stanbon(75887)

Question 65862: if (6t+7a)/4=t, then what is 4t in terms of a?
the answer is -14a i would like to know how to get that answer.
thank you
Click here to see answer by josmiceli(19441)

Question 65955: 3x - 5(3x - 7) = 2(x + 9) + 45
3x-15x-35=2x+18+45
-12x-35=2x+63
(-12x-35)+35=2x+63+35
-12x =2x+98
-12x-2x=2x+98-2x
-10x=98
-10x/-10=98/-10
x=-9 8/10 or -9 4/5
Click here to see answer by shermalaine(1)

Question 65958: A bus leaves a station at 1 P.M., traveling west at an aver-age
rate of 44 mi/h. One hour later a second bus leaves the same station, traveling
east at a rate of 48 mi/h. At what time will the two buses be 274 mi apart?
Click here to see answer by chitra(359)

Question 65954: 2(x -3) - 3(x + 5) = 3(x - 2) - 7
Click here to see answer by chitra(359)

Question 65979: The length of a rectangular playing field is 5 ft less than twice its width.
If the perimeter of the playing field is 230 ft, find the length and width of the field

Click here to see answer by uma(370)

Question 65996: A common mistake when solving equations is the following:
The equation: 2(x -2) = x +3
First step in solving: 2x -2 =x +3

Write a clear explanation of what error has been made. What could be done to avoid this error?

Click here to see answer by uma(370)

Question 66018:
How do you multiply this set of matrices? [5 4 8] _\/ {-8 6} [3 -4 -2] ^/\ { 0 -2} The first matrix is a 2x3 and the second one is a 2x2.

Click here to see answer by Edwin McCravy(20054)

Question 66010: Solve the following system of equations algebraically:
9x^2 + y^2 = 9
3x � y = 3
Click here to see answer by Edwin McCravy(20054)

Question 65952: 2(x -3) - 3(x + 5) = 3(x - 2) - 7
Click here to see answer by praseenakos@yahoo.com(507)

Question 65999: Martina leaves home at 9 A.M., bicycling at a rate of
24 mi/h. Two hours later, John leaves, driving at the rate of 48 mi/h. At what time will John catch up with Martina?

Click here to see answer by stanbon(75887)

Question 66103: Trying to help my son logically solve following problem (rather than using guess and check):
(t^2) + m = 28
t + (m^2) = 148
Solve for t and m.
Thanks

Click here to see answer by Nate(3500)

Question 66153: for the equation , the sum of the roots is twice the product of the roots. Find a.
Click here to see answer by stanbon(75887)

Question 66180: 31x � 8(3x � 0.745) = 6x + 0.205
Click here to see answer by stanbon(75887)

Question 66180: 31x � 8(3x � 0.745) = 6x + 0.205
Click here to see answer by checkley71(8403)

Question 66181: �3(10x � 3) + 10(3x � 3) = x � 7
Click here to see answer by algebrapro18(249)

Question 66181: �3(10x � 3) + 10(3x � 3) = x � 7
Click here to see answer by checkley71(8403)

Question 66185: 6x � 0.37 = 5(x � 0.28)
Click here to see answer by checkley71(8403)

Question 66175: I'm not sure if this is Linear Algebra, but i have a good feeling. So:
Suppose Y varies directly with the square of W and the cube of X. When W=4 and X=2, Y=72. Find Y when W=1 and X=5.
I'm having problems setting the problem up and I don't know what it means when it says it varies directly with the (square, cube, etc..) of X (or whatever).
Much appricated thanks!
Click here to see answer by stanbon(75887)

Question 66263: MS.SPEEDI IS PLANNING ON STARTING AT THE FINISH LINE AND WALKING TOWARD THE STARTING LINE WHEN THE RACE STARTS.IF SHE WALKS ONE METER PER SECOND AND MEETS DINA 11 SECONDS AFTER THE START OF THE RACE,HOW LONG IS THE RACE?
Click here to see answer by stanbon(75887)

Question 66466: Okay i dont know what it is with fractions but this one has me stumped, thank you in advance for your help!
1+1/5y =2/15y+ 3/2
Thanks again!
Click here to see answer by ptaylor(2198)

Question 66468: Evaluate the formula by using the given information.
S=a/1-r: Find S for a=12 and r= 1/3.
If anyone can help me with this one I would greatly appreciate it!

Click here to see answer by stanbon(75887)

Question 66699: What is wrong with this arguement? Suppose x and y represent two real numbers, where x > y
2 > 1
2(y-x)> 1(y-x)
2y-2x>y-x
y-2x>-x
y>x
The final inequality, y>x, is impossible because we were initally given x>y.
Extra info in problem possibly the "arguement"...This is a true statement . Multiply both sides by y-x. Use the distribtive property . Subtract from both sides. Add 2x to both sides.
Click here to see answer by Nate(3500)

Question 66406: i don't understand substitution or elimination.
Click here to see answer by checkley71(8403)

Question 66845: Linear? If true,what is the next ordered pair?
1.)
X Y
0 -5
3 -1
6 3
9 7
2.)Linear? If true,what is the next ordered pair?
X Y
3 -5
4 5
5 6
6 1
Click here to see answer by checkley71(8403)

Question 66855: Find the slope of the line containing the indicated points.
(-2,8) and (-2,-1)
Click here to see answer by checkley71(8403)

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