Questions on Algebra: Quadratic Equation answered by real tutors!

Tutors Answer Your Questions about Quadratic Equations (FREE)

Question 111727: For what values of k does the equation 2x squared + (1-k)x+8=0 have a double root? I have tried numerous ideas, but cannot figure this out.
Click here to see answer by scott8148(6628)

Question 111767: can someone please help me.
A. Find the corresponding y values for x=-2,-1,0,1,2,3,if y=x^2-x-2
answer(fill in y column)
x_____________y
-2
-1
0
1
2
3
B. use microsoft exel to plot the points found in part A and to sketch the graph.
Click here to see answer by jim_thompson5910(28595)

Question 111796: I have a rectangular pen with an area of 2400 square meters. I remember that the width of the pen is 20 meters greater than the length. Find the length and width of the rectangular pen. I used the formula Let w = the width; Let w + 3 = the length; Area = lw and the instructor said that it was not a proper function because it only contained one variable. What am I doing wrong?

Click here to see answer by MathLover1(6634)

Question 111749: Use the graph of y=-x^+4x+5 to answer the following:
-x^+4x+5=0 explain how you obtain your answers by looking at the graph:
Does this function have a maximum or minimum?
I do not understand how to look at a graph and tell anything -
Click here to see answer by ankor@dixie-net.com(15656)

Question 111790: x squared+4x-3=0
Click here to see answer by jim_thompson5910(28595)

Question 111852: Find the roots of 2x to the second power-5x+1=0
Click here to see answer by jim_thompson5910(28595)

Question 111872: Determine whether the graph of each parabola opens upward or downward.
y=-1/2x2+3
Click here to see answer by checkley71(8403)

Question 111875: Find the vertex and intercepts. Sketch the graph.

g(x)=x^2+x-6
Click here to see answer by checkley71(8403)

Question 111874: Determine whether the graph of each parabola opens upward or downward.
y=-1/2x2+3
Are the ordered pairs x=-3 and 2 1/2 and y=3 and -10?
Click here to see answer by MathLover1(6634)

Question 111876: This one has me stumped on how to start. Given the formula A=p(1+r/t)^nt, answer the following problem: Find r given (A)=$95375, (p)=$65,750, and t=15 years with interest compounded monthly. Here's the formula I had after I plug every thing in to the formula: $95375 = $65750 (1+r/12)^(12*15 or 180)
How do I start solving for r?
Click here to see answer by jim_thompson5910(28595)

Question 111879: Someone PLEASE help me! I am solving and graphing parabolas and I just dont understand the steps involved....I also need to graph each one and find the vertex's and intercepts?? I dont know what to do first...no has explained this to me so I can understand. Here is an example of what I am working on: f(x)=-3x^2 + x -5
I would appreciate any help!
Thanks so much!
Bonnie Cook
Click here to see answer by jim_thompson5910(28595)

Question 111699: The path of a falling object is given by the function s = -16t + vt + st where v represents the initial velocity in ft/sec and s represents the initial height in feet.
A.) If a rock is thrown upward with an initial velocity of 64 feet per second from the top of a 25-foot building, write the height (s) equation using this information.
B.) How high is the rock after 1 second?
C.) After how many seconds will the graph reach maximum height?
D.) What is the maximum height?
Click here to see answer by scott8148(6628)

Question 111947: the product of two consecutive positive integers is 306. we need to find the integers
Click here to see answer by ankor@dixie-net.com(15656)

Question 111946: How do I find out the graphing for -x^2+4x+5=0
Click here to see answer by checkley71(8403)

Question 112101: x2+7x+10=0 I guess
Click here to see answer by jim_thompson5910(28595)

Question 112228: Here is the problem: Suppose you are tossing an apple up to a friend on a third-story balcony. After x seconds, the height of the apple in feet is given by h=-16x(squared)+38.4x+0.96. Your friend catches the apple just as it reaches its highest point. How long does it take for the apple to reach your friend, and at what height above the ground does your friend catch it.
I tried doing:
-38.4/2(-16)= 6/5
Then i plugged 6/5 into the equation and got 24. I do not know where to go from there. Thank you!
Click here to see answer by ankor@dixie-net.com(15656)

Question 112182: I am given three points on a graph (14,0), (10.5,1), (6.5,3) and am asked to find the equation for the parabola that passes through these points. I understand that the parabola must be positive and open upwards. Also, I know that the "c" value must be 14 because that is the y intercept. But, from then on, I really have no idea what to do. Could you please help me?
Click here to see answer by Edwin McCravy(8909)

Question 112302: I am not sure which Algebra section this question fits under. Hopefully someone can help me figure this out. I am lost.
I am trying to find the vertex of the function:
f(x)=x^2 -8x -6
Thank you!
Click here to see answer by jim_thompson5910(28595)

Question 112305: y^2-12y+36=49
c^2+16c+64=15
Click here to see answer by jim_thompson5910(28595)

Question 112558: x^2+45=-18x
Click here to see answer by josmiceli(9686)

Question 112615: I am having a hard time writing the formula needed in order to solve this equation; A farmer wishes to fence in a pasture along a straight highway. The pasture is to contain 500 sq ft of land and be rectangular. If the fencing along the highway is heavy duty and costs $3 per foot, while the material for the remaining three sides costs $2 per foot, find the dimensions of the pasture with the minimum fencing cost.
Click here to see answer by scott8148(6628)

Question 112514: A lidless box is constructed from a square peice of tin by cutting a 10cm square from each corner and bending up the sides for the box. If the volume of the box is 1200cm cubed, find the dimensions to the nearest tenth of a centimetre.
Click here to see answer by ankor@dixie-net.com(15656)

Question 112726: y=2x^2-(3x-5)
Click here to see answer by MathLover1(6634)

Question 112700: I had to solve a quadratic equation by factoring and I recived it back as incorect. I dont know what I did wrong...could someone please explain this to me and show the correct steps if possible. I did not get 2 solutions for x and I cant figure out how to do this.
Thanks so much.
3x^2+11x-20=0
3x^2+15x-4x-20=0
3x(x+15)-4(x+5)=0
(3x-4)(x+5=0)

Click here to see answer by jim_thompson5910(28595)

Question 112866: how do I solve: x2-12x +4=0. Please help.
I have to use the quadratic formula, but don't know what it is
Click here to see answer by solver91311(16897)

Question 112557: 4z^2=9
Click here to see answer by ankor@dixie-net.com(15656)

Question 112881: Please help solve this problem for me thank you.
If f(x)=2x^-7x+3 find f(2), and find f(-3) please show detail work. Thank you again.
Click here to see answer by jim_thompson5910(28595)

Question 112883: Please help solve this problem for me I am having a hard time my instructor is not making it easy. Thank you
Solve 2x^-3x-2=0 using quadratic formula. show detail work. Thank you again
Click here to see answer by jim_thompson5910(28595)

Question 112941: Thank you so much for the answer earlier I really apprecate it. I have one final question of the day hope you can help me out. Thanks again
if a rock is thrown upward with an initial velocity of 64 feet per second from the top of a 25 foot building write the a) height(s) equation using this information typing hint:t^2
b) how high is the rock after 1 second, show work
c)after how many seconds will the graph reach maximum height, show work
d)what is maximum height, show work

If you can help me with this it will save my life thank you again.
Click here to see answer by bucky(2189)

Question 112928: it's a word problem.
Nancy wants to buy a mat for a photographtaht measures 14 in by 20 in. She wants to have an even border around the picture when it is mounted on the mat. If the area of the mat is 352 in squared How wide will the border be? I know the anwser is 1 inch. I just don't see why.

Here's what I've tried.
A=LW
(14+x)squared (20+x)Squared
280+14x + 20x+xSquared
280+34x+xsquared=0
Since this can't be factored i subtracted the 280 from both sides and got
x2 +34x = -280
half of 34 is 17 and 17 times 17 is 136
So this becomes
x2 +34x + 136 = -144
(x-72)squared = -144
x-72 = sqare root of -144
x-72 = 12i
x=72+or-12i
but this doesn't equal 1 inch. Please help me
Click here to see answer by scott8148(6628)

Question 113094: 4x^= 13x + 12
Am I right by stating that there is no solution to this problem?
Click here to see answer by solver91311(16897)

Question 113289: the height in feet of a projectile after t seconds is given by h(t)=-16t^2 +96t
determine the values for which the projectile is at the ground.
(the -16 has an exponent of 2 I couldn't get it to show up right also I need to set this problem up as an equation the chapter we are working on has to do with factoring.)
Click here to see answer by SHUgrad05(58)

Question 113291: A square is represented by 4x^2 +28x+49 inches squared. Find the length of a side of the square in terms of x
( I need to set this up in equation format and solve.)
Click here to see answer by Earlsdon(6287)

Question 113287: 4x -12y =5
-x +3y = -1
how do you solve this using the substitution method
Click here to see answer by MathLover1(6634)

Question 113295: The product of two odd Intergers is 143. Write an equation whose solution is one of the Intergers. Use Factoring to solve the equation and find both Intergers.
Click here to see answer by checkley71(8403)

Question 113519: An object is projected upward from the top of a tower. Its distance in feet above the ground after t seconds is given by s(t)=-16t+64t+80. How many seconds will it take to reach ground level?
Click here to see answer by stanbon(57361)

Question 113530: Fitting a quadratic model to data
Throughout the twentieth century, the eating habits of Americans changed noticeably .Americans started consuming less whole milk and butter and started consuming more skim and low fat milk and margarine. We also started eating more poultry and fish. In this project you will have the opportunity to investigate trends in per capita consumption of poultry during the twentieth century .
We will start by finding a quadratic model y=ax^2+bx+c that has ordered pair solutions that correspond to the data for US. Per capita consumption of poultry given in the table .To do so, substitute each data pair into the equation. Each time, the result is an equation in three unknown: a,b, and c. Because there are three pair of data, we can form a system of three linear equation equations in three unknowns .Solving for the values of a, b, and c gives a quadratic model that represents the given data.
US PER CAPITA CONSUMPTION OF POULTRY (IN POUNDS)
YEAR X POULTRY CONSUMPTION Y (IN POUNDS)
1909 9 11
1969 69 33
2001 101 66
Write the system of equations that must be solved to find the values of a, b, and c needed for a quadratic model of the given data.
Solve the system of equations for a, b c.
Write the quadratic model for the date. Note that the variable x represents the number of years after 1990.
In 1939 the actual U.S per capita consumption of poultry was 12 lbs per person. Based on this information, how accurate do you think this model is for years other than those given in the table?
Use your model to estimate per capita consumption of poultry in 1950.
According to the model, in what year was per capita consumption of poultry 50 pounds per person?
In what year was the per capita consumption of poultry at its lowest level? What was that level?

Click here to see answer by stanbon(57361)

Question 113411: I have a problem that is not from the textbook. My teacher has assigned the following problem and we are to use applications of the quadratic formula. I don't see how to put the problem into a square in order to use the quadratic formula. Here is the problem:
The rate of a bicyclist is 5mph faster than the rate of a runner. The bicyclist travels 12 miles in the same amount of time that it takes the runner to travel 8 miles. Find the rate of the runner.
This is how far I got:
12/x+5 = 8/x then, 8x - 12x +40 = 0
I would really appreciate any help. Thank you in advance.
Tynk

Click here to see answer by Fombitz(13828)

Question 113602: Use the quadratic formula to solve the equation
-
3x^2-40x=59
Click here to see answer by checkley71(8403)

Older solutions: 1..45, 46..90, 91..135, 136..180, 181..225, 226..270, 271..315, 316..360, 361..405, 406..450, 451..495, 496..540, 541..585, 586..630, 631..675, 676..720, 721..765, 766..810, 811..855, 856..900, 901..945, 946..990, 991..1035, 1036..1080, 1081..1125, 1126..1170, 1171..1215, 1216..1260, 1261..1305, 1306..1350, 1351..1395, 1396..1440, 1441..1485, 1486..1530, 1531..1575, 1576..1620, 1621..1665, 1666..1710, 1711..1755, 1756..1800, 1801..1845, 1846..1890, 1891..1935, 1936..1980, 1981..2025, 2026..2070, 2071..2115, 2116..2160, 2161..2205, 2206..2250, 2251..2295, 2296..2340, 2341..2385, 2386..2430, 2431..2475, 2476..2520, 2521..2565, 2566..2610, 2611..2655, 2656..2700, 2701..2745, 2746..2790, 2791..2835, 2836..2880, 2881..2925, 2926..2970, 2971..3015, 3016..3060, 3061..3105, 3106..3150, 3151..3195, 3196..3240, 3241..3285, 3286..3330, 3331..3375, 3376..3420, 3421..3465, 3466..3510, 3511..3555, 3556..3600, 3601..3645, 3646..3690, 3691..3735, 3736..3780, 3781..3825, 3826..3870, 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