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

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Question 51988: Find the x intercepts.
y=x^2-9x+20
Click here to see answer by THANApHD(104)

Question 52025: Hi, I have to suppose the vertex of the parabola y=3x^2-6x+k is (1,2) I have to find k.
I have substituted x=1 and y=2 into the equation and got
2=3(1)^2 - 6(1) +k
2= 3-6+k
2-3+6=k
k=5
Is this right??? thanks.
Click here to see answer by rapaljer(4671)

Question 52024: Hi, I have to find the vertex and axis of symmetry of the parabola
y= -x^2+6x+3
I also have to find if it opens upward or downward. I have done this so far:
a= -1 b=6 c=3
Vertex occurs when x= -b\2a = -6\2(-1) = 3
Then y=f(3)= -1(3)^2+6(3)+3
=12
Vertex (3,12).
It is downward because a<0
I am not sure on the axis of symmetry and how to work it out.
greatly appreciated if you could please help

Click here to see answer by rapaljer(4671)

Question 52138: To Whom It May Concern:
I have beeen having problems with algebra II every since i started and most of the time i just don't get the problems. Righ now in class we are doing something called Linear Equations and somethong that has to do with systems. So can you please just give me the easest way possible to understand these type of problems because sometimes it gets fustrating.
Sincerly,
Daniel Whitaker
Click here to see answer by josmiceli(19441)

Question 52215: Solve the system. Enter the solution coordinates.
2x - 4y = 7
4x + 2y = 9
Click here to see answer by funmath(2933)

Question 52247: solve each sytem by graphing.
x + y = 6
x - y = 2
Click here to see answer by scoop(27)

Question 52245: Could you help me to better understand how to graph linear equations in two variables? In simple easy to understand terms.
1. 2x + 3y = 12
this is my solution
2(0) + 3y =12
0 + 3y/3 = 12/3
y = 4
x = 0
2. x-y = 2

Click here to see answer by rchill(405)

Question 52237: How do you find the equation of a line satisfying the given conditions: perpendicular to x=2 and passing through the point (3,4)?
Click here to see answer by rapaljer(4671)

Question 52236: How do you find the equation of a line satisfying the given conditions: Vertical line passing through (2,-7)?
Click here to see answer by rapaljer(4671)

Question 52235: How can you find the slope-intercept form of the line perpendicular to y=-3x, passing through the point (o,-3)?
Click here to see answer by THANApHD(104)

Question 52478: Hi,

We did linear equations last week in class, and now we've moved on to graphing, but I can't do my homework because I still don't understand the linear equations yet!

On the blackboard, our teacher explained that the answer to:

x + 2y = 0

is

y = -1/2x

If someone could explain how our teacher got to that answer, I'd REALLY appreciate it!!

Also, the book we're using said to just guess a number for x, and then figure out y... does that mean everyone will get a different answer?

Thanks,
~ Jasmine

Click here to see answer by checkley71(8403)

Question 52234: How can you find the slope-intercept form of the line perpendicular to y=-3x, passing through the point (o,-3)?
Click here to see answer by darq(90)

Question 52512: Write the equation in standard from for the line that contains the given point with the given slope.
(1,0); m=3
Click here to see answer by darq(90)

Question 52513: Find an equation in standard from for each line that satisfies the given conditions.
Parallel to the x-axis and passes through (-1,3)
Click here to see answer by darq(90)

Question 52548: 5x+10-6x+3=6-2x-2
Click here to see answer by checkley71(8403)

Question 52523: A line is passing through the points (-1,1) adn (-2,-1).
What is the lope and what is the equation of the line and what are the x and y intercepts?
Click here to see answer by checkley71(8403)

Question 52572: In class we are working on reviewing writing linear equations. i know how to solve or write an equation when i have a slope and a point, and i also know how to solve when i have two points. My teacher however forgot to give us notes on how to solve when they give us an x-intercept and a y-intercept. For example:
x-intercept=3, y-intercept=2.
Could you please help me?

Click here to see answer by Nate(3500)

Question 52654: Determine if each of the following is a relation or a function. Tell why and give the domain and range of each one.
a) (0,1)(4,1)(6,2)(2,0)
b) y=6 over 2x-1
Click here to see answer by funmath(2933)

Question 52885: Solve the system of equations: (hint: let (1/x)=t and (1/y)=u)
(2/x)+(1/y)=11
(3/x)-(5/y)=10
Click here to see answer by funmath(2933)

Question 52958: Page 326 #12. A merchant mixed 10lb. of cinnamon tea with 5lb. of spice tea. The 15-pound mixture cost $4o. A second mixture included 12 lb. of cinnamon tea and 8 lb of spice tea. The 20-pound mixture cost $54. Find the cost per pound of the cinnamon tea and the spice tea. how do I solve this problem?
Click here to see answer by funmath(2933)

Question 53173: I am having trouble solving this equation its so simple but i cant remember please help.
5x-3y=4
y-x=-2
solving by substitution method please show me how to solve I am not getting the answer right.
Click here to see answer by checkley71(8403)

Question 53283: This is a word problem. Sally bought 3 chocolate bars and a pack of gum and paid $1.75. Jake bought 2 chocolate bars and 4 packs of gum and paid $2.00.Find the cost a chocolate bar and the cost of a pack of gum. This is what I have done; 3x + 1y = 1.75; 2x+4y = 2.00.
3x + 1y = 1.75; -8x - 16y = -8.00 (multipling by -4)
17y = -6.25; y= 0.37

3x + 1(0.37)=1.75
3x + 0.37 = 1.75
3x = 1.38
x = 0.46
When Checking; 3(0.46) + 1(0.37)=1.75
1.38 + 0.37 = 1.75
1.75 = 1.75 (true)
Te problem is when I plug these numbers into the second equation it does not come out to 2.00 it comes out as 2.40. Please tell me what I am doing wrong.

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

Question 53271: I have a word problem that I cannot seem to figure out.
One number is 12 more than another. The sum of the smaller number and twice the larger is 39. Find the larger number.
No matter how I try to work out this problem it comes out wrong. Please Help!!!
Click here to see answer by ankor@dixie-net.com(22740)

Question 53307: I have to solve the following system by addition:
5x - 3y = 13
4x - 3y = 11
I have tried using the example from our text and I come out with x=2, y= -1 but when Y check these #'s into the equations they do not work. Please help.
Click here to see answer by funmath(2933)

Question 53285: Will you please solve the system by addition or substitution
3x-4y=8
6x-2y=10
thankyou
Click here to see answer by funmath(2933)

Question 53284: Will you please solve the system by subtraction
3x-y=-7
x+y=-9
thankyou
Click here to see answer by funmath(2933)

Question 53315: This is a word problem. One number is 12 more than another. The sum of the smaller number and twice the larger number is 39. Find the larger number.
I do not even know where to begin on this problem. Please Help!!!!!
Click here to see answer by stanbon(75887)

Question 53365: how do you solve a problem that says parallel to the y-axis and passes through (-5,-2)? Thanks
Click here to see answer by funmath(2933)

Question 53399: if two given equations are being solved so that one unknown is eliminated by the method of comparison which of the following steps is essential? (A )6 x 7-2Y/3 -5y=8 or (B) 7-3x/2=6x-8/5 i got (B) IS THIS RIGHT ALSO solve the following equation 4ax+?by=11ab,8ax-5by=?ab ? x=? y=? i could not get this one please show formula thanks
Click here to see answer by stanbon(75887)

Question 52734: Find an equation in standard from for this line.
A line with a slope of -2 that goes through the point (1,-3)
Click here to see answer by stanbon(75887)

Question 53441: Find an equation in standard form of the line passing through the point (2,5) with slope m=5
Click here to see answer by ankor@dixie-net.com(22740)

Question 53486: Mr. McKelvey finds that flying with the wind he can travel 1188 miles in 6 hours. However, when flying against the wind, he travels only 2/3 of the distance is the same amount of time.
Find the speed of the plane in still air and the wind speed.
Click here to see answer by checkley71(8403)

Question 53440: find the x- and y- intercepts and slope of the graph of each equation.
13.y= -x
Click here to see answer by checkley71(8403)

Question 53496: A furniture shop refinishes chairs. Employees use two methods to refinish a chair. method I takes 1 hour and costs $3. Method II takes 1 1/2 hours and material costs $1.50. Last Week, they took 36 hours and spent $60 refinishing chairs. How many did they refinish with each method?
Click here to see answer by stanbon(75887)

Question 53045: find the slope and the intercepts of each line.
f(x) = 4/5x + 7...............4/5 is 4 over 5.
Click here to see answer by rchill(405)

Question 53669: 12&1/9 - 4&2/3

4/10 x 30/60 x 6/10
Please help
Click here to see answer by stanbon(75887)

Question 53677: This is a question involving 3 variables, solve by elimination:
2x - 5y + 3z = -1
x + 4y - 2z = 9
x - 2y - 4z = -5
Click here to see answer by funmath(2933)

Question 53731: -8(4+9x)=7(-2-11x)

I tried to isolate the variable..but then I realized I don't know how to...Thanks if you can help.
Click here to see answer by Earlsdon(6294)

Question 53732: 4(2a-a)=1/7(49a+70)

The 1/7 is a fraction...Thanks for the help if you can...
Click here to see answer by Earlsdon(6294)

Question 53749: A line contains the points C (4 1/2, -3) and D (6 1/2, 6) What is the slpe of all lines perpendicular to CD?
Click here to see answer by rchill(405)

Question 53734: please hlep me with this equation
-8(4+9x)=7(-2-11x)
Thanks
Click here to see answer by rchill(405)

Question 53730: 6(y+2)-4=-10

I have no idea....Thanks if you can help...
Click here to see answer by rchill(405)

Question 53729: 7+3x=x-4(2+x)

I have no idea hw to solve that problem. I tried doing -7 on both sides, but it didn't come out right.. Thanks for help
Click here to see answer by rchill(405)

Question 53729: 7+3x=x-4(2+x)

I have no idea hw to solve that problem. I tried doing -7 on both sides, but it didn't come out right.. Thanks for help
Click here to see answer by stanbon(75887)

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