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Recent problems solved by 'smartdude17'
smartdude17 answered: 27 problems
Quadratic_Equations/4115: Find the vertex and intercepts for each quadratic function. Does it open up or down? y = -3x^2 + 6x
1 solutions
Answer 1817 by smartdude17(30)   on 2005-06-26 18:42:24 (Show Source):
You can put this solution on YOUR website!Your problem is easy, even a 7th grader can do it. The intercepts are 2 and 0. You get it by doing the QF. You find the vertex by also using the QF. To find a vertex use : -b/2a. In this case the answer is 1. So, your parabola, or parabolic curve, is turned downward.
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percentage/3948: What is 10% of $35.00 and What is 10% of $30.00? Also what is 10% of $15.00?
1 solutions
Answer 1733 by smartdude17(30) on 2005-06-21 16:56:48 (Show Source):
You can put this solution on YOUR website!This one is easy! My teacher told me a little saying. When multiplying by a 10, move the decimal one place to the left. But this only works on tens. Answer is: 3.5 , 3.0 , and 1.5
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Quadratic_Equations/1931: y=-3x^2+2x+7
I am still a little lost on this type of problem.
1 solutions
Answer 803 by smartdude17(30) on 2005-05-12 16:16:57 (Show Source):
You can put this solution on YOUR website!I am going to show you step by step:
y=-3x^2+2x+7
 After you do all the substitutions.
 Since this technology doesn't let me do the work
without showing ERROR. I am going to show you
the answers.
x= -40/19 (-2 2/19), 21/19 (1 2/19)
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Polynomials-and-rational-expressions/1922: z(5z-1)=3z(z+3)
"solve by suitable methods"....whatever that means. :)
1 solutions
Answer 739 by smartdude17(30) on 2005-05-11 17:50:49 (Show Source):
You can put this solution on YOUR website!z(5z-1)=3z(z+3) Well, first you need to clear parenthesis.
5z^2-z=3z^2+9z Invert to = the formula.
2z^2=10z Now you invert 10z so it resembles the formula.
2z^2-10z=0 Do QF.
AFTER YOU DO THE WORK (THIS THING KEEPS SAYING I DID IT WRONG!) THE ANSWER =:
z=5,0 Let's Check!
5(25-1)=15(8)
120=120
0(0-1)=0(0+3)
0=0
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Inequalities/1920: I am working on solving this inequality and could really use some help.
(x-3)/(x+4)>2
Thanks :)
1 solutions
Answer 737 by smartdude17(30) on 2005-05-11 17:41:47 (Show Source):
You can put this solution on YOUR website!(x-3)/(x+4)>2 Multiply everything by CD. Change sign to =.
(x-3)/(x+4)=2](x+4) Simplify.
x-3=2x+8 Finish the equation.
-11=x, -11< x
(-10-3)/(-10+4)>2
-13/-6 > 2
2 1/6 > 2 IT CHECKS.
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Quadratic_Equations/1697: Solve the inequality, state the solution set using interval notation
1/2x^2 is greater than/or equal to 4-x
1 solutions
Answer 617 by smartdude17(30) on 2005-05-09 17:56:47 (Show Source):
You can put this solution on YOUR website!1/2x >/= 4-x
1/2x = 4-x]2
x=4-x
2x=4
x=2
x >/= 2
1/2(4) > 4-4
2>0
This is your answer. I am sorry but I don't understand what you mean by interval notation. Sorry. Hope it helps!
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Quadratic_Equations/1791: When using the quadratic formula what if the answer does not equal 0 like this one; -x + 6 = 5x^2
1 solutions
Answer 614 by smartdude17(30) on 2005-05-09 17:42:08 (Show Source):
You can put this solution on YOUR website!-x+6=5x^2 Invert to formula
0=5x^2+x-6 Solve regularly
x= -6/5, x= 1 These are your answers. They should check. Let's see:
0=5(1)^2+1-6
0=0 This checks. Let's try the next one:
0=5(-6/5)^2-6/5-6
0=0/5 This also check because 5 goes into 0, 0 times.
After this work, mabey you did something wrong like mabey you made a sign error.
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Quadratic_Equations/1671: I have no clue how to do this. I am working on quadratic functions and their graphs in intermediate algebra. This is one question with three parts:
A. Write the function y=3(x-2)^2+6 in the form of Y=ax^2 +bx+c, and find the
vertex of the parabola using the formula x=-b/2a
B. Repeat part (a) with the functions y=-4((x-5)^2-9 and y=3(x+2)^2-6.
C. What is the vertex for a parabola that is written in the form y=a(x-h)^2+k?
Explain your answer.
1 solutions
Answer 565 by smartdude17(30) on 2005-05-07 18:00:32 (Show Source):
You can put this solution on YOUR website!WOW, I've already finished this topic and I'm in seventh grade(lol). Well to find the vertex of a parabola, you use -b/2a. Your equation is this and I'll try to help you solve it from the way you have written it.
y=3(x-2)^2+6
Now you would clear the parenthesis by:
y=3(x^2-4)+6 this turns into this:
y=3x^2-12+6
Now you need to simplify it:
y=3x^2-6
Now you can do the QF (quadratic formula)
 Substitution
And this is your scantron answer. Or you could do method #2.
So this is 
And now you M.A.D. it by multiplying 17 and 8 then adding 8 which equals 144/17 and then you multiply it with 1/6 which equals 24/17 and -24/17
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Functions/1714: Think of a mathematical function that represents something from your own life. For example, suppose the number of beers you drink depends on the number of football games you watch. If you drink five beers every football game, the function would be Number of Beers (B) = 5 times Number of Football Games(F), or B=5F.
Write a brief paper describing this function that comes from your own life. It could be something about the amount of money you spend, the number of hours you spend on the phone, etc...
1 solutions
Answer 562 by smartdude17(30) on 2005-05-07 17:27:33 (Show Source):
You can put this solution on YOUR website!OK, for your information, I do not help the way you need. This really isn't a mathematical problem. It is more like a short story you have to write. Say if I help 10 kids every time there is a basketball game on T.V.. For two weeks I helped because of the games. How many did I help? Well I helped(tutored) 140 kids. So is this what you're looking for?
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Linear-equations/1664: Solving the equation
Problem
4Y+7=5Y+13
I know the answer is -6
But I need a breakdown, when I first tried to complete this problem I subtracted 7 from both sides but I was left with 9Y (4Y+5Y), I just need a break down I am doing someting wrong.
Thanks
Helpless in Durham
1 solutions
Answer 560 by smartdude17(30) on 2005-05-07 17:00:41 (Show Source):
You can put this solution on YOUR website!Oky-doke. Step-by-step:
4y+7=5y+13 Given
Invert the 5y.
-y+7=13
Invert the 7.
-y=20
Now divide the minus.
-y/- = 20/-
Your answer: y=-20
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Quadratic_Equations/1711: Quadratic_Equations/1699: Using the quadratic formula for x in the equation 2x^2=11x-9 results in which of the following values:
A. -9/2 or 1
B. 9/2 or -1
C. 9/2 or 1
D. -9/2 or -1
Thanks for any help you can give me on this question!!
1 solutions
Answer 553 by smartdude17(3) on 2005-05-07 13:43:30:
When you do all the work, it comes to the answer C. 9/2 and 1. That means you got it right!!!!!!!!!!
Can someone show me how you derive the answer to this question. I need to know how to figure this out as well. (Guess I should have said that...lol)
1 solutions
Answer 559 by smartdude17(30) on 2005-05-07 16:54:34 (Show Source):
You can put this solution on YOUR website!Sure, I'll show you. It's the same person who answered it last time.
2x^2=11x-9 Given
2x^2-11x+9=0 Invert,lety=0
 QF
 Sub
 S
 S
And after you do the adding and subtracting, it will leave you with this:
9/2 and 1
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Inequalities/1658: how do you solve this quadratic equation.y >/= x^2-3x+1
1 solutions
Answer 557 by smartdude17(30) on 2005-05-07 16:36:56 (Show Source):
You can put this solution on YOUR website!Very simple. I will show you:
y >/= x^2-3x+1 G
0=x^2-3x+1 lety=0,let sign be=
QF
 Sub,S
And this is your answer. It is in the radical form. There is no sqrt of five besides 2.24. And besides, this is the scantron answer. Good Luck in all of your other problems!
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Linear-equations/1665: I'm having trouble with solving systems. I did this before, at the beginning of the year, but I completely forget how to do it. Here's the system:
y=7x-9
y=4x+6
1 solutions
Answer 556 by smartdude17(30) on 2005-05-07 16:13:59 (Show Source):
You can put this solution on YOUR website!Well for a system you start like this:
0=7x-9 G,lety=0
0=4x+6
4x+6=7x-9 Merge by Sub
15/3=3x/3 S
5=x Solution
4(5)+6=7(5)-9 Sub
26=26
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Quadratic_Equations/1695: -10x^2+11x+24=20
1 solutions
Answer 555 by smartdude17(30) on 2005-05-07 14:26:37 (Show Source):
You can put this solution on YOUR website!In order to solve this, you have to start with the first step. I'll show you:
-10x^2+11x+24= 20 G
-10x^2+11x+44= 0 I,S
QF
 Sub,S
 S
Now do some thinking. Is 1881 a perfect? If it isn't, you do this:
 S
 S, (answer #1)
 S, (answer #2)
In the two answers, M.A.D. them. It means to multiply, add, and divide. Or you could do it this way which leaves it at a radical:
Now think! What times what is 1881? Well 9*209=1881, so 9 is a perfect leaving 209 in the sqrt.
And that is your radical answer.
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Inequalities/1698: Solve the inequality, state the solution set using interval notation
1/2x^2 is greater than/or equal to 4-x
1 solutions
Answer 554 by smartdude17(30) on 2005-05-07 13:55:39 (Show Source):
You can put this solution on YOUR website!I don't know what you mean by interval notation, but this is what I got:
1/2x^2 >/= 4-x G
1/2x^2 >/= 4-x]2 I(CD)
x^2 >/= 8-2x S
x^2+2x-8= 0 I,change to =
(x+4)(x-2)= 0 FoiL (you can also do the QF)
x+4=0, x-2=0 Set all terms to zero
x=-4, x=2 Isolate,S
And here are your answers. If you have to graph it, use -b/2a.
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Quadratic_Equations/1320: y=-5xsquared
1 solutions
Answer 481 by smartdude17(30) on 2005-05-01 19:27:35 (Show Source):
You can put this solution on YOUR website!y=-5x^2 is easy!
You need to set "y" to zero (0)and you also need to know that you're adding zeros(0) to it:
0=-5x^2+0+0
Now you do the quadratic formula:
Then substitue by pluging in numbers with the letters(ax^2+bx+c)
And simplify:
And this is your answer. Some answers are usually radicals.
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