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

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Question 306258: The equations S = 5000 + 200x and
D = 9500 - 100x express the supply S and the
demand D, respectively, for a popular compact disc brand
in terms of its price x (in dollars).
a) Graph the equations on the same coordinate system.
b) What happens to the supply as the price increases?
c) What happens to the demand as the price increases?
d) The price at which supply and demand are equal is
called the equilibrium price.What is the equilibrium
price?
Click here to see answer by checkley77(12569)

Question 306390: 31x=62(x+3)
My work: 31x=62x+186
divide 31 from both sides
x=2x+6
divide 2 from both sides
1/2x=6
x=3
My online homework told me it was wrong but I don't understand what I did wrong.
Click here to see answer by Fombitz(13828)

Question 306441: x+ 8y = 5
x = 4-8y
Click here to see answer by richwmiller(9143)

Question 306509: A chemist has one solution that is 40% alcohol and another that is 55% alcohol. How much of each must she use to make 15 liters of solution that is 50% alcohol?
Click here to see answer by dabanfield(803)

Question 307001: 2x-9y=2
Click here to see answer by ichudov(499)

Question 307002: 2x-9y=2 y=?
Click here to see answer by Alan3354(30993)

Question 307029: Please help me solve this question
( 3x +9 =108

my email is jscott659@yahoo.com
Click here to see answer by jim_thompson5910(28598)

Question 307170: Find the solution to each system by the substitution method. Check your answer
10x+3y=8
2x+ y=2
Click here to see answer by Fombitz(13828)

Question 307362: I am REALLY struggling with this one.
You mix your own feed for the puppies. The feed mix consists of ground meat and ground grains. You mix a total of 100 pounds at a time. The ground meat is 45% protein and the ground grains is 18% protein, find the amount of ground meat and ground grains required for a 100 pound feed mix at the optimum protein level of 28%. Solve this system using the Elimination Method. Round solutions to nearest whole number. The system of equations that I thought should be used is: m + g = 100 and 0.45m + 0.18g = 0.28 but I cannot come up with a sensible solution. Please help!
Click here to see answer by ankor@dixie-net.com(15660)

Question 307509: Perform an operation on the given system that eliminates the indicated variable and solve for the unknown variables.
x-4y+z=3
y-3z=10
3y-8z=24
Click here to see answer by rapaljer(4667)

Question 307569: The position of an object moing in a straight line is given by s=2t^2-3t, where s is in meters and t is the time in seconds the object has been in motion. how long (to the nearest tenth) will it take the object to move 19 meters?
i think my answer is 3.7 seconds.
Click here to see answer by Earlsdon(6287)

Question 307657: Al sold a total of 300 Pizzas and Gyros. Pizzas were sold at $8 each and Gyros for $6. Total sales came to $2,000. How many of each was sold?
Click here to see answer by checkley77(12569)

Question 307885: √36x^3
Click here to see answer by mananth(12270)

Question 308004: write an equation with points of (0,4) and (7,-4) (I'm not sure where this line of question should go...)
Click here to see answer by JBarnum(2044)

Question 308200: Alex has a jar containing 80 coins, all of which are either quarters or nickels. The total value of the coins is $14.95.
A. Write a system of equations for the problem.
B. How many of each type of coin does he have?
Click here to see answer by nyc_function(2733)

Question 308558: (3a^8)(a^6)
Click here to see answer by Alan3354(30993)

Question 308558: (3a^8)(a^6)
Click here to see answer by rapaljer(4667)

Question 308751: y= x-4
y= -x+2 how to solve by substition
Click here to see answer by rapaljer(4667)

Question 308817:
how do I solve by elimination? I can do substitution.
Click here to see answer by ichudov(499)

Question 309181: Please help..
solve:
1)4x + 3y =7
2) 16x + 12y = 28

Thank you so much....Rebecca
Click here to see answer by JBarnum(2044)

Question 309181: Please help..
solve:
1)4x + 3y =7
2) 16x + 12y = 28

Thank you so much....Rebecca
Click here to see answer by nyc_function(2733)

Question 309181: Please help..
solve:
1)4x + 3y =7
2) 16x + 12y = 28

Thank you so much....Rebecca
Click here to see answer by jim_thompson5910(28598)

Question 309239: - 5/u+6=4
Click here to see answer by straight C+'s(8)

Question 309239: - 5/u+6=4
Click here to see answer by Alan3354(30993)

Question 309466: Im REALLY stuck on this Algebra Equasion, Please Help Me!!!
I have these 2 formulas
12-x^2 -2xy = 0
...12-y^2 - 2xy = 0
...
for some reason x and y are both 2
how do you get this
i tried and got
y= 6/x -0.5x tried to sub into second one but gets messy any way to do this on a calculator by any chance but i want to know how to do it algebraically hmmmmm........
Click here to see answer by stanbon(57384)

Question 309523: Math You agree to pour water into cups for the Booster Club at a football game. The pitcher contains 64 ounces of water when you begin. After you have filled 8 cups, the pitcher is empty and must be refilled.
Write a function to represent the arithmetic sequence.
Click here to see answer by stanbon(57384)

Question 309555:
Click here to see answer by ichudov(499)

Question 309722: 3y+3(1-y)-y=6
Click here to see answer by rfer(12666)

Question 309872: 5x+5y=-13, 7x-3y=11 using the elimination method solve this please.
Click here to see answer by jim_thompson5910(28598)

Question 308689: x = -y :
3x

---

1

---

x+y
Click here to see answer by Alan3354(30993)

Question 310081: Word problem:
Translate the problem into a pair of linear equations in two vaiables. Solve the equations using either elimination or substitution. State your answer for the specified variable.
A garage owner wants to fill a 55-gallon drum with a 20% winter mixture of antifreeze for his customers. How many gallons of 100% antifreeze should he mix with some 10% antifreeze mixture in order to fill the drum?
I'm having difficulty writing equations from a word problem. Please show me the equations you created and steps to get to the answer. Please also show the answer. Thank you so much!
Click here to see answer by josmiceli(9697)

Question 310097: A company has sales (measured in millions of dollars) of 50, 60, and 75 during the first three consecutive years. Find a quadratic function that fits these data, and use the result to predict the sales during the fourth year. Assume that the quadratic function is of the form y = ax2 + bx + c
Click here to see answer by ankor@dixie-net.com(15660)

Question 310351: (1,-4,3) IS THE SOLUTION TO THE SYSTEM
x+y+z=0
x+y+5z+20
5x+y+z=4
Click here to see answer by Fombitz(13828)

Question 310456: -5(k+4)>3(k-4)
Click here to see answer by stanbon(57384)

Question 310486: -5-8f>59
Click here to see answer by JBarnum(2044)

Question 310493: 8a+2-10a<20
Click here to see answer by JBarnum(2044)

Question 310520: 3a+8/2<10
Click here to see answer by unlockmath(1603)

Question 310807: what value of b will make the system y=2x+7 and y=2.5x+b intersect at the point (-1,5)?
Click here to see answer by stanbon(57384)

Question 311043: please help me solve this problem: y= 2x + 10 find y if x = -2
Click here to see answer by Fombitz(13828)

Question 311066: Determine whether (2,7) is a solution of 6x+9y=20. Is (2,7) a solution of the equation? Please advise. Find the indicated outputs for f(x) =4x^-4x. f=(0), f=(-1), and f=(2). Thank you.
Click here to see answer by Fombitz(13828)

Question 311081: On three consecutive passes, a football team gains 6 yards, loses 24 yards, and gains 14 yards. What number represents the total net yardage? The total net yardage in yards is what? Please help. Thank you.
Click here to see answer by checkley77(12569)

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