Questions on Algebra: Quadratic Equation answered by real tutors!

Tutors Answer Your Questions about Quadratic Equations (FREE)

Question 745939: please help me solve this equation (2x-9)(x+8)=0
Click here to see answer by savvyhush23(50)

Question 746086: I need help solving this Quadratic equation problem. I would appreciate it... If someone who may help walk me through steps to solving this problem. I need to learn this for my final that's coming up.
[Travel Speed (mph), Braking Distance (ft)]
[20(mph), 20 (ft)]
[40(mph), 105 (ft)]
[60(mph), 300(ft)]
a)Find a quadratic function that fits the data on the right.
b) Use the function to estimate the braking distance of a car that travels at 50 mph.
c) Does it make sense to use this function when speeds are less than 10 mph? Why or why not?
y=ax^2+bx+c
[20(mph), 20 (ft)] (20)=a(20)^2+b(20)+C = 20=400a+20b+C
[40(mph), 105 (ft)](105)=a(40)^2+b(40)+C = 105=1600a+40b+C
[60(mph), 300(ft)] (300)=a(60)^2+b(60)+C = 300=3600a+60b+C
Click here to see answer by stanbon(75887)

Question 746156: f(x) = (x − 5)2 + 2
i need a axis of symmetry
Click here to see answer by tommyt3rd(5050)

Question 746222: If the discriminant of a quadratic equation is equal to zero how many real, distinct roots can it have?
Click here to see answer by rfer(16322)

Question 746245: what is the factor of ?
Click here to see answer by nerdybill(7384)

Question 746300: is there any quadratic equation which has more than two roots because i have studied so far that whatever be the highest power of the variable we have that much roots only.But someone told me that there are more than two roots in an quadratic equation.
Click here to see answer by KMST(5328)

Question 746465:
Click here to see answer by tommyt3rd(5050)

Question 746475: When can you solve a quadratic equation by using the square root function?
Click here to see answer by solver91311(24713)

Question 746539: The length of a rectangle is 4 m. more than the width. The area is 30 m^2. Find the width and length.
I know that the equation is w(w+4)=30, I figured out that much. I also know that you have to distribute: w^2+4w=30. But I'm so lost on what to do next.
Click here to see answer by rothauserc(4718)

Question 746640: Find the zeros of the quadratic function: y=xsquared+7x+12
Click here to see answer by reviewermath(1029)

Question 746893: find value of A, B, C, and D!
the quadratic function which takes the value 41 at x=-2 and the value 20 at x=5 and is minimized at x=21
Y=Ax^2 - Bx + C
the minimum value is D
Click here to see answer by MathLover1(20849)

Question 746899:
Click here to see answer by jim_thompson5910(35256)

Question 746974: How do you solve quadratic equations like 10x^2+28x+16=0?
Click here to see answer by jim_thompson5910(35256)

Question 747021: is it possible to write two real numbers whose sum is 4 and whose product is 5? use the quadratic formula to help explain,
so far i have,
x+y=4
(x)(y)=5
Click here to see answer by tommyt3rd(5050)

Question 747031: how can you tell if the vertex is the max or min of a quadratic function?
Click here to see answer by josgarithmetic(39617)

Question 747148: What number subtracted from the numerator and denominator of 151/181 will make it equivalent to 3/4?
Click here to see answer by tommyt3rd(5050)

Question 747253: Two companies working together can clear a parcel of land in 13 hours. Working alone, it would take company A 10 hours longer to clear the land than it would Company B. How long would it take company B to clear the parcel of land alone?

Click here to see answer by josmiceli(19441)

Question 747271: I am completely stuck on this problem. It's asking me to find the product. Please help?
Click here to see answer by FrankM(1040)

Question 747322: The rational function
2 6
( )
5
x
R x
x
−
=
+
has a
Click here to see answer by lynnlo(4176)

Question 747342: h = �16t^2 + vt + c
The equation shown above is the vertical motion formula, where h is the ending height, t is the time in seconds, v is the starting velocity in feet per second, and c is the starting height in feet.
If Adam, who is 6 feet tall, threw his baseball 80 feet per second straight up into the air, which of the following answers is the best estimate of how long it took the ball to come back to the ground?
I think this is the equation, h= -16t^2+80t+6
Click here to see answer by nerdybill(7384)

Question 747356: Terry throws a ball straight up. The initial height of the ball is 3 feet and has an initial velocity of 32 feet per second. The function is modeled by:
h(t) = -16t^2 + 32t + 3
How long is the ball in flight? Round answer to nearest hundredth.
Which formula, process, etc. did you use to solve this problem?

Click here to see answer by Alan3354(69443)

Question 747376: What is the formula for h when working with parabolas?
Click here to see answer by Alan3354(69443)

Question 747652: Solve the following quadratic equation
a) 9[(y-1)/ (y+2)]^2 - 15[(y-1)/(y+2)] -6 = 0
Can you please help me out? Thanks so much in advance:
Also can you please show me the steps:)
Click here to see answer by reviewermath(1029)

Question 747658:
Click here to see answer by FrankM(1040)

Question 747657: 3x^2+5x+2
Click here to see answer by FrankM(1040)

Question 747634: I need some help with these questions.
-
14. Flight 725 left New York at 10:28 a.m. flying north. Flight 245 left from the same airport at 11:18 a.m. flying south at one hundred twenty kph less than three times the speed of flight 725. At 1:06 p.m. they are 1,030 kilometers apart. What is the average rate of speed for Flight 245?
A) 165 kph
B) 395 kph
C) 365 kph
D) 345 kph
E) 155 kph
F) 175 kph
-
15. What is the average rate of speed for Flight 725?
A) 165 kph
B) 395 kph
C) 365 kph
D) 345 kph
E) 155 kph
F) 175 kph
-
Any help would be greatly appreciated, and if you can show your steps, that would really help me to understand how I should go about tackling more problems like these in the future. Thank you for your time.
Click here to see answer by MathLover1(20849)

Question 747677: I would like some help on a problem concerning quadratic equations. Here is the problem. There are three consecutive numbers. When the largest one is squared, it is equal to 18 more than 9 times the smallest number. x^2+4x+4=9x+18. Please explain thoroughly and clearly, as I am in a deep fix. Can you also give me the three consecutive numbers? Thank you in advance
Click here to see answer by stanbon(75887)

Question 747848: A light is to be mounted on the side of a building 18ft above the ground. The closest a ladder can be placed to the building is 6ft. To the nearest foot how long of a ladder will the electrician need so that he can mount the light?
Click here to see answer by Kg2003(10)

Question 747851: Solve the equation using the square root property. 2(5x-3)^2+3=19
Click here to see answer by MathLover1(20849)

Question 747851: Solve the equation using the square root property. 2(5x-3)^2+3=19
Click here to see answer by Alan3354(69443)

Question 747982: Complete the square to write each function in the form

Click here to see answer by Edwin McCravy(20054)

Question 747983: Complete the square to write each function in the form

Click here to see answer by MathLover1(20849)

Question 747981: Complete the square to write each function in the form

Click here to see answer by MathLover1(20849)

Question 748054: For each quadratic function, (a) find the vertex, the axis of symmetry, and the maximum or minimum function value and (b) graph the function.

Click here to see answer by josgarithmetic(39617)

Question 748033: For each quadratic function, (a) find the vertex and the axis of symmetry and (b) graph the function.

Click here to see answer by josgarithmetic(39617)

Question 748171: find the quadratic function which takes the value 41 at x=-2 and the value 20 at x=5 and is minimized at x=21
Y=Ax^2 - Bx + C

Click here to see answer by Edwin McCravy(20054)

Question 748235: This doesn't make sense...Someone help me please!The equation is:
r^3=2r^2+15r
Click here to see answer by lynnlo(4176)

Question 748235: This doesn't make sense...Someone help me please!The equation is:
r^3=2r^2+15r
Click here to see answer by tinbar(133)

Question 748236: How do I solve this because I got stuck? The equation is: 14a=a^3-5a^2
Click here to see answer by lynnlo(4176)

Question 748236: How do I solve this because I got stuck? The equation is: 14a=a^3-5a^2
Click here to see answer by rothauserc(4718)

Question 748269: I came across this question, and I got completely stuck. Please help?
"A ball is thrown downward with an initial velocity of 21 meters per second from a cliff that is 90 meters high. The height of the ball is given by the quadratic equation h=-4.9t^2-21t+110 where h is in meters and t is the time in seconds since the ball was thrown. Find the time that the ball will be 60 meters from the ground. Round your answer to the nearest tenth of a second."
Click here to see answer by Alan3354(69443)

Question 748392: There are two factors of -36 such that one factor is 11 less than half of the other factor. Choose all the pairs of these factors.
the choices are
-2 and 18,
-6 and 6,
3 and -12,
4 and -9
Click here to see answer by MathLover1(20849)

Question 748443: how can i solve:
x^2+4y^2=25
x+2y=7
substitution or elimination
by solving algebraically. I get stuck on the factoring part.
Click here to see answer by MathTherapy(10552)

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