Questions on Algebra: Quadratic Equation answered by real tutors!

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Question 67147: Hi,
I seem to be having problems plotting a quadratic graph.
I have the following formula
pi r^2 + 180r - 6000 = 0
My two values for r are r(x) = 29 or r(x) = -64
However, when creating a table to create the graph, I am getting very strange values to plot the Y axis with. Such as:
r(x) = -64 so y = -30388 while r(x) = 29 y = 1862
Which in turn does not give the desirable "U" shape quadratics graph but more like a linear straight line graph.
Any help would be much appreciated
Thanks
Shaun Halliday
Click here to see answer by ankor@dixie-net.com(15649)

Question 67212: help me solve quadractic equations by graphing

2x(squared) + 4x= 6
Click here to see answer by stanbon(57307)

Question 67257: solve by completing the square. Check Both roots.
x^2-x=3/4
2x^2-9x-5=0
Click here to see answer by josmiceli(9671)

Question 67312: Solve by completing the square :
25 + x^2 = 8x
Click here to see answer by checkley71(8403)

Question 67306: Please help to solve :
2x + 3y - 2z = -3
x + 9y - 2z = 3
3x + 6y + 2z = -1
Click here to see answer by venugopalramana(3286)

Question 67302: PLease help to factor
64a^3c^6 - 27x^9
Click here to see answer by Earlsdon(6287)

Question 67424: Can you please help me this exponental problem: x^2=6x-8? Thank you!
Click here to see answer by ptaylor(2048)

Question 67503: An ecological center wants to set up an experimental garden using 300m of fencing to enclose a rectangular area of 5000m^2 Find the dimension of the garden
Click here to see answer by stanbon(57307)

Question 67474: 1) x squared+5x+6=o
2) x squared-4x+3=0

Click here to see answer by checkley71(8403)

Question 67474: 1) x squared+5x+6=o
2) x squared-4x+3=0

Click here to see answer by meg1650(2)

Question 67539: Solve the following equation for x. [Do not report answers in decimal – leave them in radical form, and be sure to simplify radicals.
25x^2 = 13
Click here to see answer by 303795(595)

Question 67542: Find two consecutive positive integers such that the sum of their squares is 85. [You must use algebra to solve this, setting up an equation with a variable, and using algebra to solve for the variable.]
This one has me so confused. I need help, please????
Click here to see answer by 303795(595)

Question 67543: A garden area is 30 ft long and 20 ft wide. A path of uniform width is set around the edge. If the remaining garden area is 400 ft2, what is the width of the path? Give your answer in decimal form, rounded to the nearest thousandth.

Click here to see answer by aaaaaaaa(138)

Question 67544: Solve the following quadratic equation by completing the square:
2x^2 +10x + 11 = 0

Click here to see answer by venugopalramana(3286)

Question 67514: A resturaunt sells about 330 sandwhiches each day at a price of $6 each. For each $.25 decrease in price, 15 more sandwhiches are sold per day. How much should the restauraunt charge to maximize daily revenue? What is the maximum daily revenue?
Click here to see answer by ankor@dixie-net.com(15649)

Question 67541: Solve the following quadratic equation by completing the square:
x^2 – 6x – 3 = 0

Click here to see answer by ankor@dixie-net.com(15649)

Question 67506: a landscape architect has included a rectangular flower bed measuring 9ft by 5ft in her plans for a new building. She wants to use two colors of flowers in the bed, one in the center and the other for a border of the same with on all four sides. If she had enough plants to cover 24ft^2 for the border, how wide can the border be?
Click here to see answer by ankor@dixie-net.com(15649)

Question 67540: Solve the following equation for x. [Do not report answers in decimal – leave them in radical form, and be sure to simplify radicals.
2(x – 5)^2 = 3
Click here to see answer by ankor@dixie-net.com(15649)

Question 67642: y2-3y+2=0
Click here to see answer by brandonpark2889(31)

Question 67692: Solve the following equation for x. Hint: Factor the left hand side. [Do not report answers in decimal – leave them in radical form, and be sure to simplify radicals.
x^2 + 4x + 4 = 7
I have come up with x = 2 +or- sqrt7. Is this a correct answer??? I would appreciate if someone could let me know howe I am doing. Thanks.
Click here to see answer by brandonpark2889(31)

Question 67713: how do I find the area of a equilateral triangle by only knowing one side of it which is ten ft. I know this is not where I submit this problem but I have a hard time finding the right place to go thank you
Click here to see answer by ankor@dixie-net.com(15649)

Question 67720: 5. x2+4x+3
6. x2+6x-2
10. 3x2+4x-5
14. -4x2+8x+1
Click here to see answer by stanbon(57307)

Question 67738: I have a square field with an area x + 12 by x + 12. A section of it has been removed, and that area is x + 1 by x + 7. The area of the square minus the missing section is 217.
The equation is (x + 12)^2 - (x + 1)(x + 7) = 217.
I tried using the distributive property to get x^2 + 24x + 144 - x^2 + 8x + 7 = 217.
Then I get stuck. If I combine x^2 and -x^2, I no longer have a quadratic equation, (which is the section we're studying).
What should I do? Thanks for your help.
GJL
Click here to see answer by Earlsdon(6287)

Question 67793: please help to expand
(x^-1/4 - y^2/3)^2
Click here to see answer by stanbon(57307)

Question 67816: A company uses the formula C(x)= 0.02x^2-3.4x+150 to model the unit cost in dollars for producing x stabilzer bars. For what number of bars is the unit cost at its minimum? What is the unit cost at that level of production?
Click here to see answer by venugopalramana(3286)

Question 67809: Why does the graph of a quadratic intercept the y-axis at only one point? Does the graph of a quadratic always intercept the x-axis in two points? Give examples.

Click here to see answer by venugopalramana(3286)

Question 67943: Directions:Solve each of the equations for x.
Problem# 22
25x^2=13

Directions: Solve each equation for x.
Problem# 32
2(x-5)^2=3
Directions: Solve each equation for x.
Problem#42
x^2+4x+4=7 (Hint:Factor the left-hand side)
Click here to see answer by tutorcecilia(2152)

Question 67989: Use the arithmetic sequence of numbers 2, 4, 6, 8, 10… to find the following:
a) What is d, the difference between any 2 terms?
Answer:
Show work in this space.

b) Using the formula for the nth term of an arithmetic sequence, what is 101st term?
Answer:
Show work in this space.

c) Using the formula for the sum of an arithmetic sequence, what is the sum of the first 20 terms?
Answer:
Show work in this space.

d)Using the formula for the sum of an arithmetic sequence, what is the sum of the first 30 terms?
Answer:
Show work in this space.

Click here to see answer by venugopalramana(3286)

Question 68069: I have asked this question within the past two days without a response. I am having a tough time figuring out how to set this problem up. Once I know how to set it up and why, I can probably solve the equation. I hope someone out there can help me with this one, please.
Find two consecutive positive integers such that the sum of their squares is 85. [You must use algebra to solve this, setting up an equation with a variable, and using algebra to solve for the variable.]
Click here to see answer by Earlsdon(6287)

Question 68077: Here is another problem that I have posted within the past 2 days that I am having trouble with setting up. If someone could give me a little hint, I would appreciate it. Thanks.
A garden area is 30 ft long and 20 ft wide. A path of uniform width is set around the edge. If the remaining garden area is 400 ft2, what is the width of the path? Give your answer in decimal form, rounded to the nearest thousandth.
Click here to see answer by checkley71(8403)

Question 68138: I had a problem I was working on with the quadratic equation rule.

Eventually I worked the problem down to
The answer I'm suppose to get from there is
I don't see how this is possible.
Click here to see answer by stanbon(57307)

Question 68137: solve the following:
18x^2 + 9x - 2 = 0
Click here to see answer by funmath(2925)

Question 68240: ) Logarithms:
a) Using a calculator, find log 1000 where log means log to the base of 10.
Answer: 10^3=1000; therefore log1000=3

b) Most calculators have 2 different logs on them: log, which is base 10, and ln, which is base e. In computer science, digital computers are based on the binary numbering system which means that there are only 2 numbers available to the computer, 0 and 1. When a computer scientist needs a logarithm, he needs a log to base 2 which is not on any calculator. To find the log of a number to any base, we can use a conversion formula as shown here:
log b A=log a/log b
Using this formula,log 2 1000 find . Round your answer to the hundredth's place.
Answer:
Show work in this space.

Click here to see answer by stanbon(57307)

Question 68364: PLease help to evaluate :
x^2 - x^3y - xy if x = -1/2 and y = -1/4
Click here to see answer by checkley71(8403)

Question 68373: Find the equation of the line that passes through (4,2) and is perpendicular to the line 3y - 2x = 5
Click here to see answer by checkley71(8403)

Question 68371: Please help to solve using the quadratic formula :
-3x^2 - 4 = 2x
Click here to see answer by checkley71(8403)

Question 68426: -x+y=1
2x+y=-2
Click here to see answer by rmromero(383)

Question 68406: 6x^3 = 18x + 60x^2
SOLVE
Click here to see answer by checkley71(8403)

Question 68671: Problem: x^2+7x=1
This is the answer I got, is it correct?
x = -7/2 ±√53/2
Click here to see answer by rmromero(383)

Question 68674: Question: x^2+3x = 1
This is the answer that I got, is it correct?
x =-3/2 ±√13/2
Click here to see answer by rmromero(383)

Question 68672: Question: x^2+26x=-68
This is the answer that I got, is it correct?
x =-13 ±√101
Click here to see answer by josmiceli(9671)

Question 68680: If the area of this rectangle is 105cm2 then the length is ____cm, the width is ____ cm, and the perimeter is ____cm. The width of the rectangle is (x) and the length is (2x+1). This is all the information the problem gives me. The problem was given to me on a study guide along with the answer key. The length is 15cm, and the width is 7 but I dont understand how they came about this answer. Can you please help me??
Click here to see answer by Earlsdon(6287)

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