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

Tutors Answer Your Questions about Linear-systems (FREE)

Question 198232: If 5x-6y = -123 and 3x + 13y = -107, what is the value of x and y?
Click here to see answer by jim_thompson5910(28715)

Question 198241: y=x-7
2y-x=-10
what is the solution to the above system of equations ?
thank you.
Click here to see answer by jim_thompson5910(28715)

Question 198238: A man goes into a grocery store and buys a grapefruit and a toy ball. A 7% tax is applied to the price of non-food items. If the total bill is $5.15, including $0.18 in tax on the toy ball, what are the prices of the grapefruit and the ball?
Click here to see answer by anantha(86)

Question 198244: Joe has a collection of nickels and dimes that is worth $5.65. If the number of dimes were doubled and the number of nickels were increased by 8, the value of the coins would be $10.45. How many dimes does he have?
Click here to see answer by RAY100(1637)

Question 198243: An express and local train leave GraysLake at 3 P.M. and head for Chicago 50 miles away. The express travels twice as fast as the local and arrives 1 hour ahead of the local. Find the speed of each train.
Click here to see answer by anantha(86)

Question 198240: On the first day of school, the percentage of boys in a particular class is 60%. During the school year, six girls move away, and are replaced in the class by six boys; this makes the class roster 75% boys. Find the number of boys and girls in the class on the first day of school.
Click here to see answer by anantha(86)

Question 198271: x+y=7
x-y=1
Solve the system of equations by graphing. Then classify the system.
Use the graphing tool to graph the system. If both equations yield the same line, graph the line twice.
Click here to see answer by arallie(162)

Question 198292: I need help with this one that is using the substitution method.
7m+n=48
m-6n=13

Click here to see answer by jim_thompson5910(28715)

Question 198292: I need help with this one that is using the substitution method.
7m+n=48
m-6n=13

Click here to see answer by arallie(162)

Question 198242: Walt made an extra $9000 last year from a part-time job. He invested part of the money at a 9% annual rate of interest, and the rest at an 8% annual rate of interest. At the end of the year, he made a total of $770 in interest. How much was invested at 8%?
Click here to see answer by checkley77(12569)

Question 198335: I need to help using the substitution method for
9x+4y=-32
x=1-5y
any help would be great
Click here to see answer by jim_thompson5910(28715)

Question 198340: Which one is more linear? 644.2x-1e+06, 1019.7x-2e+06,8454.8x-2e+07 This was done on excel.
Click here to see answer by stanbon(57967)

Question 198364: This question has been confusing me and I really need some help. Thank You!
Find the solution of the system of equations by graphing.
y=-x+9
y=4x-1
Thank you again!
Click here to see answer by arallie(162)

Question 198374: Solve the system of equations by graphing
x-y=2
x+y=6

Click here to see answer by arallie(162)

Question 198374: Solve the system of equations by graphing
x-y=2
x+y=6

Click here to see answer by jim_thompson5910(28715)

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(2825)

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(28715)

Question 198730: I dont have a booklet I am stding witha final review
Click here to see answer by solver91311(17077)

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(31530)

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(6812)

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(28715)

Question 198900: if 4x-3y=11 and -5x+2y=-12, then the solution (x,y) is ?
Click here to see answer by jim_thompson5910(28715)

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(15746)

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(1512)

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(28715)

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(1861)

Question 199083: 4x+5y=20
Click here to see answer by user_dude2008(1861)

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(28715)

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(28715)

Question 199051: {5x + 3y= 7
{x - 6y = 8
Click here to see answer by rfer(12730)

Question 199259: {3x - 2y=4
(x + 2y=8 (linear combination)
Click here to see answer by Alan3354(31530)

Question 199266: linear combination
{2x + y=7
{4x 2y=5
Click here to see answer by checkley77(12569)

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

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