Questions on Algebra: Systems of Linear Equations answered by real tutors!

Tutors Answer Your Questions about Linear-systems (FREE)

Question 1029049: I need to know how to use both elimination and substitution methods on the linear equation 8x-3y=-16
5x+2y=-41
Click here to see answer by ikleyn(52785)

Question 1029434:
Click here to see answer by Alan3354(69443)

Question 1029772: A boy invested $860 of his Bar Mitzvah money. He put part of it in the bank at 4.5% interest and lent the remainder to his parents at 7%. If after one year the interest on these investments was $51.95. Find how much he put in the bank.
PLEASE USE SYSTEMS OF EQUATIONS AND SHOW YOUR WORK !!!
Click here to see answer by josmiceli(19441)

Question 1029771: Lilian has part of $9000 invested at 4% and the remainder at 6%. His annual return on each investment is the same. At what rate would she have to invest all her money to get the same interest?
PLEASE USE SYSTEMS OF EQUATIONS AND SHOW YOUR WORK !!!
Click here to see answer by addingup(3677)

Question 1029826: find the slope-intercept form of the equation of the line that passes through the given point and has the indicated slope m. Sketch the line.
(0,-4), m=7
Click here to see answer by Fombitz(32388)

Question 1029877: A random variable X has given the possible values of 1,2,3. Given the E(x)=2 and E(x^2)=5. Find the probability that (x=1) (x=2) (x=3).
PLEASE HELP!
Click here to see answer by Fombitz(32388)

Question 1029980: X-y=6
2x-3z=16
2y+z=4
Click here to see answer by Fombitz(32388)

Question 1030013: twice the square of a certain whole number added to 3 times the number gives 90. find the number

Click here to see answer by FrankM(1040)

Question 1030315: The sum of two numbers is 25. The sum of the smaller and 6 times the larger is 125. Find the numbers.
Click here to see answer by mathmate(429)

Question 1030388: Hello,They could help me with this exercise please:
x+y=-1 2x-3y=5
Click here to see answer by josgarithmetic(39617)

Question 1030412: (1) ax + by = c
(2) dx + ey = f

Ralph is trying to solve the system of equations. He begins by subtracting Ax from both sides of equation (1), and then he divides the equation by B. Before he can continue, his friend Alice comes along and says, "No, you should have subtracted By from both sides, and then divided by A. You will get the wrong answer. Thanks!
Click here to see answer by Edwin McCravy(20056)

Question 1030626: how many solutions would there be to this equation?:
4x-6y=5
-0.08x+0.10y=0.10
Click here to see answer by Edwin McCravy(20056)

Question 1030661: 5x+y+6z = −1
4x−y+4z = 1
3x−y+4z = −9
what is x, y , z?
Click here to see answer by josgarithmetic(39617)

Question 1030709: Find critical points of the following functions
F(x)=(x^2-1)^2
I used the chain rule and I got f'(x)=2(x^2)*2x and now I did f'(0) where 2x=0 but I can't find the critical points. I am not good with them. Can anyone help me?
Click here to see answer by stanbon(75887)

Question 1030766: use slope and y intercept to graph
p(x)=-2x+9
Click here to see answer by josgarithmetic(39617)

Question 1030813: 6w+4>5w+4
Click here to see answer by rfer(16322)

Question 1030959: Solve this pair of simultaneous equations by the substitution method:
y - 3y + 1 = 0
3x + 2y = 16
Click here to see answer by stanbon(75887)

Question 1031010: what would the graph look like for these equations?
b) 2x+3y=12
y=2x-3
c) x+y=10
y=3x+2
Click here to see answer by ewatrrr(24785)

Question 1031027: Solve this pair of simultaneous equations by substitution method:
y - 3x + 1 = 0
3x + 2y = 16
Click here to see answer by LinnW(1048)

Question 1031190: Two years ago Philip was three times as old as his son.
Two years hence, twice his age will be equal to five times
that of his son. Find their present ages.
Click here to see answer by josmiceli(19441)

Question 1031216: y+8=-4/3(x-2)
Click here to see answer by Alan3354(69443)

Question 1031216: y+8=-4/3(x-2)
Click here to see answer by stanbon(75887)

Question 1031314: In Lesson 2.3, you used the following data about population changes in the United States. Suppose state planners in Indiana and Michigan think that the average rate of change will continue through 2015
Click here to see answer by richard1234(7193)

Question 1031421: if y is equal to 2x+7 determine y if x is equal to 3
Click here to see answer by Fombitz(32388)

Question 1031393: Timmy has three times as much money invested at 5% bonds as he has in stocks paying 7%. If his annual income from the stocks and bonds is $158.40, how much has he invested in bonds?
USE SYSTEMS OF EQUATIONS TO SOLVE !!!
Click here to see answer by josmiceli(19441)

Question 1031677: Find the value(s) of "k" so that the system is inconsistent:
x + y + 3z = 1
x + ky + 3z = 1
x + 2y + kz = 3
Click here to see answer by Fombitz(32388)

Question 1031756: What would be the equation, standard form, and slope intercept for this question. "Liza made a necklace with two different sizes of beads.the total length of the necklace is 20 inches. Each red bead is 1 inch long and each black bead is .5 inch long. Write an equation to represent the number of red beads, r, Liza will need for the necklace"?
Click here to see answer by josmiceli(19441)

Question 1031760: What is the standard form and slope intercept form of this question. "A landscaper uses 10 gallons of water for every 3 trees he waters during a drought. What is the total number of gallons,g, he uses for t number of trees"?
Click here to see answer by josmiceli(19441)

Question 1031754: What would be the equation, the standard form, and the slope intercept of this question. "A landscaper uses 10 gallons of water for every 3 trees he waters during a drought. What is the total number of gallons, g, he uses for t, number of trees?"
Click here to see answer by josgarithmetic(39617)

Question 1031744: Rationalise the denominator of √14-1 /√14
Click here to see answer by Cromlix(4381)

Question 1031792: The sum of the two digits of a two-digit number is 6.
When 18 is added to the number the digits are reversed.
Find the number.
Click here to see answer by Edwin McCravy(20056)

Question 1031802: Solve the given Linear system by
Reducing its augmented matrix to reduced echelon form
Cramer�s Rule
Using matrices
10x+4y-2z=-4
-3w-17x+y+2z= 2
w + x+y = 6
8w-34x+16y-10z=4
plz sir solve this question.....

Click here to see answer by Fombitz(32388)

Question 1032022: I'm so close to solving this question but any input would be so greatly appreciated! I'm having trouble coming up with the right 3 equations for this problem:
"The sum of three numbers is 14. The first number minus three times the third number is the second number. The second number is six more than the first number. Find the three numbers."
Thank you for any input.
Click here to see answer by Boreal(15235)

Question 1032021:
Click here to see answer by ikleyn(52785)

Question 1032024: This problem is absolutely stumping me...any help would be appreciated.
"A student scored a total of 258 points on three tests. The total of her first two scores was 80 points more than her third score. She scored 13 points more on her third test than on her second. What were her scores on all three tests?"
Thank you
Click here to see answer by fractalier(6550)

Question 1032168: n/2-3n/4+5n/6=21

Click here to see answer by stanbon(75887)

Question 1032250: I need help solving sytems of equations word problems. An example of one is: Sally makes dolls for a living. She sells dolls for 21$ each. Her expenses for producing the dolls are 1000$ for the sewing machine plus 12$ per doll for materials. How many dolls must she sell to break even?
Click here to see answer by rfer(16322)

Question 1032382: Maximize the following objective function using simplex method:
Z=10 X_(1 )+8 X_2
Subject To:
3 X_1+1X_2 ≤4500
2 X_1+2X_2 ≤4000
X_1+3X_2 ≤4500
With
X_1 ≥0
X_2 ≥0

Click here to see answer by johb(2)

Question 1032604: Attempting to create Leontief Model (as part of an open-ended project on the model)�where can I find the appropriate data?
Click here to see answer by fractalier(6550)

Question 1032688: Find the maximum value of y subject to; , , and Please help me!
Click here to see answer by Edwin McCravy(20056)

Question 1032733: solve the following systems
x − 2y = 6
−7.5x + 15y = −45
Click here to see answer by josgarithmetic(39617)

Question 1033065: Maximize x+y+z subject to
x+y is x+z is y+z is Also know that x,y,z is >or= 0
Click here to see answer by stanbon(75887)

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