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

Tutors Answer Your Questions about Linear-systems (FREE)

Question 263512: If a pharmacist wants to make 150 milliliters of a 20 percent alcohol solution, but only has a 30 percent alcohol solution and a 15 percent alcohol solution, how much of each solution should she mix together to get what she needs?
Could you please take me step by step?
Click here to see answer by josmiceli(19441)

Question 263606: I need to graph on a plane. y>-1. Where do I begin?
Click here to see answer by stanbon(75887)

Question 263627: A hockey team determines that it needs at least 60 points for the season in order to make the playoffs. A win w is worth 2 points and a tie t is worth 1 point. Find and graph an inequality that describes the sisuation. Please help.
Click here to see answer by drk(1908)

Question 263824: A pen contains chickens and goat. There are a total of 40 heads and 130 feet. How many chicken and how many goat are in the pen?
I have the answer: 25 goat and 15 chicken, however, I do not know how to set up the equation. Please help
Click here to see answer by Greenfinch(383)

Question 264229: Hi there, I was wondering whether or not there is a method to solving this called a graphing method.
Click here to see answer by Alan3354(69443)

Question 264210: 3x - 2y = 11
x - y/2 = 4
how do i solve these equations using substation?

Click here to see answer by checkley77(12844)

Question 264208: x + 14y= 84
2x - 7y = -7
how do i solve these equations using substation?

Click here to see answer by checkley77(12844)

Question 264282: how do you solve the system by substitution?
3X+2Y=11
x=13-3y
Click here to see answer by Alan3354(69443)

Question 264295: y=2x
x+y=12 What is the answer in (x,y) form
y=1/3x+6
3y-x=24 What is the answer in (x,y) form
3x+2y=13
5x=2y+11 What is the answer in (x,y) form
6x-2y=6
x+2y=8 What is the answer in (x,y) form
Click here to see answer by JBarnum(2146)

Question 264309: I am working with systems of Linear Equations. Confused. can you show me step by step how to solve
-2x + y = 1 and 3x + y = 1
Click here to see answer by unlockmath(1688)

Question 264343: need help solving a problem
-4x-6y+15=0
Click here to see answer by JBarnum(2146)

Question 264372: x-2y=-1
-x+5y=4
Click here to see answer by Alan3354(69443)

Question 264432: how do i slove this system
3x+5y=-3
10y-2z=2
x=-z
Click here to see answer by Alan3354(69443)

Question 264538: solve:
3x-2y=12
2x+3y=-5
by the addition method

solve:
2x-1y=-5
3x-5y=-4
by substitution

show steps please.
Click here to see answer by jim_thompson5910(35256)

Question 264664: I need to learn how to do this problem? In need of some serious help
3x - 5y = 1
10y = 6x - 1
Click here to see answer by palanisamy(496)

Question 264665: I am needing some help with these math problems, I can't seem to grasp it.
x - y =4
2x + y = 5
Click here to see answer by palanisamy(496)

Question 264708: I can't figure out how to solve this word problem:
Flying to Kampala with a tailwind a plane averaged 158 km/h. On the return trip only averaged 112km/h while flying back into the same wind. Find the speed of the wind and the speed of the plane in still air.
Click here to see answer by Alan3354(69443)

Question 264663: Solve each System Of linear equations.
{y=2x-3}
{y-2x= -3}
we are solving Special systems.
Click here to see answer by Alan3354(69443)

Question 264711: solve by eilimination
1)3x+7y =48
5x-7y= -32
2)-2x+3y =25
-2x+6y=58
3)3x+8y = 81
5x+6y=-39
4)8x+13y=179
2x-13y=-69
Click here to see answer by Edwin McCravy(20056)

Question 264737: Please help!
2x - 4y = 8
x - 2y = 4
Click here to see answer by jim_thompson5910(35256)

Question 264736: Here is another problem that I am confused with. Some of the problems are one way and then they are changed around and that when I get lost.
y = 2x + 1
x + y = 4
Click here to see answer by jim_thompson5910(35256)

Question 264741: I don't have a clue how to work this one out. I worked it out but it was wrong on the quiz.

A concrete driveway has a perimeter of 280 feet. The length of the driveway is 20 feet more than 4 times its width. Find the length and width of the driveway by writing two equations with two varibles, and solving the equations by either the addition method or the substitution method.
Click here to see answer by josmiceli(19441)

Question 264851: 7x-4y=-3
2x+5y=8
Click here to see answer by mananth(16946)

Question 264985: Without graphing find the vertex

Click here to see answer by Edwin McCravy(20056)

Question 264984: Without graphing find the line of symmetry
f(x)=-(x+6)^2-8
Click here to see answer by Alan3354(69443)

Question 265117: what is 5x-2-x(1+2)=2(2+3)
Click here to see answer by Alan3354(69443)

Question 265117: what is 5x-2-x(1+2)=2(2+3)
Click here to see answer by JBarnum(2146)

Question 265135: Evaluate the following expression when r = 4 and t = 2.
(3 � rt)-1

Click here to see answer by JBarnum(2146)

Question 265150: Which expression below produces the nth term in the sequence?
24 , 30 , 36 , 42 , 48 , ...

Click here to see answer by palanisamy(496)

Question 265269: True or False. What is the y-intercept of the line y-b?
Click here to see answer by drk(1908)

Question 265288: how do I solve this linear probleam I'm confused 3x-4y=12
Click here to see answer by drk(1908)

Question 265448: Please help me solve this system of equations:
36x-15y+50z=-10
2x+25y=40
54x-5y+30z=-160
Thank you so much!
Click here to see answer by vksarvepalli(154)

Question 265448: Please help me solve this system of equations:
36x-15y+50z=-10
2x+25y=40
54x-5y+30z=-160
Thank you so much!
Click here to see answer by palanisamy(496)

Question 265445: Please help me solve this system of equations:
7x+5y+z=0
-x+3y+2z=16
x-6y-z=-18
Thank you!
Click here to see answer by palanisamy(496)

Question 265445: Please help me solve this system of equations:
7x+5y+z=0
-x+3y+2z=16
x-6y-z=-18
Thank you!
Click here to see answer by vksarvepalli(154)

Question 265477: graph the linear equation
find the 3 plotting points
-2x-3y=-7
Click here to see answer by stanbon(75887)

Question 265459: x - 25y = 30 & y = -34x + 350
Click here to see answer by roseo(33)

Question 265563: I need help with this problem...(mainly the "give three solutions part")
Solve the system.If the system has an infinite solution set, specify it and give three solutions.If the system has no solution,say so.
x+y=4(y+2)
x-y=2(y+4)
This is what I've tried(don't know if it's anywhere close to being right)...
x+y=4y+8
x-y=2y+8
x-3y=8
x-3y=8
-x+3y=-8
x-3y-x+3y=0
Then I got stuck...I think there are infinite solutions. But it says to list three of them and I don't know.
Thanks so much for your help!

Click here to see answer by unlockmath(1688)

Question 265977: how do i solve this problem?
Carlos has recieved a 9% salary increase. if he now earns $327 per week, what was his salary before the increase?
Click here to see answer by Alan3354(69443)

Question 266105: The question is: Two cars start at the same point and travel in opposite directions. One car travels 5 mph faster than the other car. After 4 hrs, the two cars are 420 miles apart. Find the speed of each car.
One set of equations I tried was x+y=4, 5x+y=420, and another set was x+y=420, 5x+4y=420. I was unable to get the correct answers with either set of equations. Thanks for your help!!
Click here to see answer by Alan3354(69443)

Question 266128: A total of tickets were sold for the school play. The number of student tickets sold was three times the number of adult tickets sold . How many adult tickets were sold?

Click here to see answer by rfer(16322)

Question 266425: please help me solve this problem
category:coins and money
1.Alice is counting a cash register at the end of the night.she has $1015 in $5 bills and $10 bills.if she has 138 bills all together,how many of each type does she has?
please help me right away.
Click here to see answer by checkley77(12844)

Question 266438: please solve for x and y.
mixture problem.
1.a chemist want to make 75 liters of 16% acid solution.he is going to make it by mixing a 10% acid and a 25% acid solution.how many liters of each will he need?
please answer this problem right away.I NEED YOUR HELP

Click here to see answer by ankor@dixie-net.com(22740)

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