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

Tutors Answer Your Questions about Linear-systems (FREE)

Question 198654: "Make up a word problem that results in the following linear programming problem:
maximize z=5x+4y
subject to the constraints 10x+20y<=1000
30x+10y<=2000
x>=0 y>=0 "
I understand the math part of this, but I am baffled about writing a word problem. Please help! I thank you in advance!
Click here to see answer by vleith(2983)

Question 198719: {3x+4y=9
y=x-3

it says to solve the system by using substitution
idk how to do that... please help
Click here to see answer by jim_thompson5910(35256)

Question 198730: I dont have a booklet I am stding witha final review
Click here to see answer by solver91311(24713)

Question 198728: Radio signals travel at a rate of meters per second. How many seconds will it take for a radio signal to travel from a satellite to the surface of the Earth if the satellite is orbiting at a height of meters?
Click here to see answer by Alan3354(69443)

Question 198745: One year ago Walt invested $12000. He invested part of the money at 7% and the rest at 9%. He made a total of $970 in interest. How much was invested at 7%?
I do not know where to place what number in the formula equation
ax2 + bx + c = 0
Click here to see answer by checkley75(3666)

Question 198776: Please find the slope:
(2,3), and (5,-3).
Thank you.
Click here to see answer by MathLover1(20850)

Question 198842: Please help me solve:
Soybean meal is 14% protein; cornmeal is 7% protein. How many pounds of each should be mixed together in order to get 280lbs mixture that is 12% protein?
How many pounds of the cornmeal should be in the misture?
How many pounds of the soybean should be in the mixture?
Thank you.
Click here to see answer by jim_thompson5910(35256)

Question 198900: if 4x-3y=11 and -5x+2y=-12, then the solution (x,y) is ?
Click here to see answer by jim_thompson5910(35256)

Question 198909: 4(x-1)+2=3x+8-2x
Click here to see answer by sailajasrinivasp(2)

Question 198941: {-2x + y=-1
{x + y= 5
Click here to see answer by ankor@dixie-net.com(22740)

Question 198945:
Click here to see answer by pannalal(9)

Question 198944: {-3x + y = 4
{-x + y = -2
Click here to see answer by pannalal(9)

Question 198944: {-3x + y = 4
{-x + y = -2
Click here to see answer by checkley75(3666)

Question 198944: {-3x + y = 4
{-x + y = -2
Click here to see answer by jojo14344(1513)

Question 198947: {-3x + y = 4
{-x + y = -2
Click here to see answer by pannalal(9)

Question 199040: {2x + y=7
{-5x - 2y=8
Click here to see answer by RAY100(1637)

Question 199079: 2. An express train and a local train both leave Gray�s Lake at 12:00 noon and head for Chicago 60 miles away. The express travels twice as fast as the local and arrives 2 hours ahead of it. Find the speed of each train.

I am confused by this problem and do not know where to start.
Click here to see answer by jim_thompson5910(35256)

Question 199062: {3x - y=2
{-2 + 5y=6
Click here to see answer by RAY100(1637)

Question 199084: 4x+5y=20
m=8
Click here to see answer by user_dude2008(1862)

Question 199083: 4x+5y=20
Click here to see answer by user_dude2008(1862)

Question 199061: {5x + 3y= 7
{x - 6y = 8
Click here to see answer by RAY100(1637)

Question 199100: Solve algebraically and check:
2x+4y=2
3x-6y=15
Click here to see answer by jim_thompson5910(35256)

Question 199118: I need help with an algebra word problem with system of equations.
on the first day of school, 60% of the class were boys. During the school year six girls moved away and 6 boys replaced them. At the end of the year, 75% of the class were boys. What is the number of boys and girls on the first day?
I've tried to do this:
60% of (x + y) = x
40% of (x + y) = y

Click here to see answer by jim_thompson5910(35256)

Question 199051: {5x + 3y= 7
{x - 6y = 8
Click here to see answer by rfer(16322)

Question 199259: {3x - 2y=4
(x + 2y=8 (linear combination)
Click here to see answer by Alan3354(69443)

Question 199266: linear combination
{2x + y=7
{4x 2y=5
Click here to see answer by checkley77(12844)

Question 199254: {2x + y=7
{-5 - 2y=8
Click here to see answer by tutorvolunteer(9)

Question 199464: The question is asking to solve each system by any method, if possible. If a system is inconsistent or if the equations are dependant, state this. Can you please help me solve # 39 in study set 3.2 under try it yourself.
Click here to see answer by solver91311(24713)

Question 199578: Solve the sytem of equations by graphing. Then classify the system.
x+y=15
x-y=3
Click here to see answer by jim_thompson5910(35256)

Question 199621: The difference between two numbers is 18. If the larger number is 5 more than twice the smaller number, what is their sum?
Click here to see answer by jim_thompson5910(35256)

Question 199704: I need to graph the following:
y=-1/2x+3 and y=3/2x-1
Click here to see answer by rfer(16322)

Question 199718: x+0, times y=3
show graph
is there an x-intercept? is there an y intercept? if so what is it?
Click here to see answer by stanbon(75887)

Question 199716: y=7/5x-3
solve for x
find x, and y intercept
find slope
find ordered pairs to graph
Click here to see answer by stanbon(75887)

Question 199681: i need to solve this using the substitution method
8x+2y-7=0
-2x-1y+2=0
Click here to see answer by Mathtut(3670)

Question 199927: There are 21 people in science class. Out of those 3/7 are 8th graders. how many are 8th graders?

Answer:

A. 7

B. 8

C. 9

D. 10

Click here to see answer by nerdybill(7384)

Question 199926: Nick had 1 3/4 gal of milk. How many pints of milk does Nick have?

Answer:

A. 12

B. 14

C. 16

D. 18

Click here to see answer by nerdybill(7384)

Question 199924: 3 friends decide to split the cost of food and rent evenly. They spend a total of $ 542.35 on food and $ 1257.65 on rent. Find the amount each of the 3 friends paid.

Answer:

A. 600

B. 500

C. 550

D. 650

Click here to see answer by nerdybill(7384)

Question 199934: graph the following equation and identify the y-intercept: y=x+1, it makes me give 3 different answers to plot
Click here to see answer by Alan3354(69443)

Question 200112: x^2+y^2+2x-4y-4=0 complete square and state the center and the radius or the circle
Click here to see answer by orca(409)

Question 200121: -x+4y=-11
2x+4y=-2

Click here to see answer by jim_thompson5910(35256)

Question 200189: Your dad is 34 years older than your brother. Five years ago, your dad was three times as old as your brother. How old are they now?
What I know already:
x-y = 34
Click here to see answer by jim_thompson5910(35256)

Question 200258: please help me!! solve this equation
2x+2y=-6
Click here to see answer by checkley77(12844)

Question 200166: Hi
A rectangular piece of sheet metal with an area of 800 in^2 is to be bent into a cylindrical length of stovepipe having a volume of 400 in^3. What are the dimensions of the sheet metal?
thanks for the homework help!
Click here to see answer by ankor@dixie-net.com(22740)

Question 200265: Hi!
A biologist has two brine solutions, one containing 1% salt and another containing 4% salt. How many milliliters of each solution should he mix to obtain 1 L of a solution that contains 2.8% salt?
thanks for the homework help!

Click here to see answer by jim_thompson5910(35256)

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