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Number-Line/289510: Define a variable and write an inequality. Then solve. A local summer baseball team plays 20 games each season. So far, They have won 9 games and lost 2.How many more games must they win this season to win at least 75% of all their games? I know the answer is 6 more games, but I need some help with graphing the problem.
1 solutions
Answer 209692 by richwmiller(9144)   on 2010-04-07 12:37:39 (Show Source):
You can put this solution on YOUR website!Let x= number of games need to win to have 75% win
(.75*20)-9=x
The 2 games they lost is extra info meant to confuse the problem. Don't be confused
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Equations/289504: Solve: 8y^3 + 27 divided by 2xy - 10y + 3x -15
1 solutions
Answer 209685 by richwmiller(9144) on 2010-04-07 12:26:50 (Show Source):
You can put this solution on YOUR website!Solve: 8y^3 + 27 divided by 2xy - 10y + 3x -15
This is not an equation and so can't be solved. It is an expression and can be reduced or simplified.
8y^3 + 27=(2y+3)*(4y^2-6y+9)
2xy - 10y + 3x -15=(x-5)*(2 y+3)
(2y+3)*(4y^2-6y+9)/(x-5)*(2 y+3)
(4y^2-6y+9)/(x-5)
This is the furthest this can go since we have x in the denominator and and y in the numerator
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Linear-equations/289536: What is the equivalent to
3a + 4b - (-6a - 3b)
and how do you get to the answer?
1 solutions
Answer 209670 by richwmiller(9144) on 2010-04-07 10:56:19 (Show Source):
You can put this solution on YOUR website!This is not a linear equation, slope nor graph problem.
There are many equivalents not just "the" equivalent.
An equivalent is 6a+8b-(-12a-6b)
but I suspect that is not what you really meant to ask.
multiply everything in the parentheses by -1
because 3a + 4b - (-6a - 3b)
means 3a + 4b -1* (-6a - 3b)
Work out (-1)*-6a)+(-1*)*(-3b)
then add that to 3a+4b
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test/289437: Sorry i don't know what is the topic to the question i am going to ask. But what is directly proportional? It appeared in my test serveral times but i don't understand.
1 solutions
Answer 209665 by richwmiller(9144) on 2010-04-07 10:00:45 (Show Source):
You can put this solution on YOUR website!"algebra proportions' seems a likely category.
Repeating what the other tutor said
if you work 8 hours for 10 dollars you will get 80 dollars
80=8*10
p=10*h
pay = wage*hours
y=kx
Usually in those direct proportion problem you will be given a sample x and y
so you can find k
then they will either given you n x or y and want the other
John worked 8 hours and earned $64
the next day he earned $72
how many hours did he work the second day
inversely proportional
y=k/x
but that is another topic
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Trigonometry-basics/289521: prove that (sin^2)x(1+cot^2(x))=1. i don't have the slightest clue how to do this. please help. thanks
1 solutions
Answer 209658 by richwmiller(9144) on 2010-04-07 09:29:02 (Show Source):
You can put this solution on YOUR website!Just present the problem with a thank you.
Telling us that you don't have the slightest clue doesn't help solve the problem.
It just makes me wonder "Where was this person during class?"
Everyone here really needs help.
The key to this problem is trig identities.
Gather up all the trig identities that you can find especially those with sin^2 and tangent ^2 or cotangent ^2
PS Don't use x for multiplication when you also use x for an unknown.
http://www.sosmath.com/trig/Trig5/trig5/trig5.html
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Linear-equations/289389: the problem is 4x-6y=5and 2x-3y=7 am I suppose to multiple the top by a number
1 solutions
Answer 209635 by richwmiller(9144) on 2010-04-06 23:43:09 (Show Source):
You can put this solution on YOUR website!4x-6y=5and 2x-3y=7
You haven't told us what you are trying to do.
4x-6y=5
2x-3y=7
But you may notice that they have the same slope and so they are parallel and never intersect and therefore have no "solution"
-a/b= slope
-4/-6=2/3
-2/-3=2/3
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Graphs/289429: a car leaves town and drives east at 50 miles per hour. a second car leaves the same point three hours later and also drives north at 50 miles per hour. how far apart are they 4 hours after the second care leaves?
1 solutions
Answer 209630 by richwmiller(9144) on 2010-04-06 23:34:59 (Show Source):
You can put this solution on YOUR website!The first car went 3*50=150 miles before the second car left
after 4 more hours they each go 200 miles.
So the first car has gone 350 and the second car 200
the distance between them d=sqrt(350^2+200^2)=50sqrt(65)=403.11
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Inequalities/289405: how can you quickly solve for a boundary point? and what is the boundary point for 3-2x<1?
1 solutions
Answer 209628 by richwmiller(9144) on 2010-04-06 23:27:59 (Show Source):
You can put this solution on YOUR website!Since there are two questions, I will only answer the first.
I can solve them very fast. Did you see me do it?
Ok. Watch closely. I am going to do it again. Did you see me?
Based on that, I will leave the second question for you to solve.
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Rectangles/289426: How would I figure out the rectangle that was 7/8yards by 32/49 yards? And then put it into sq ft.
Thank you
1 solutions
Answer 209627 by richwmiller(9144) on 2010-04-06 23:23:16 (Show Source):
You can put this solution on YOUR website!change yards to feet first
(7/8)*3 and (32/49)*3
You didn't say what you mean by "figure out"
But you mentioned sq feet which is area.
36/7=5.14 sq ft
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Numbers_Word_Problems/289409: Use two equations with two variables to solve the problem.
The sum of two numbers is 15 less than twice the first number. Their difference is 5 less than twice the second number. Find each of the numbers.
I appreciate any help that can get me to see the equation and the solution. Thank you so much
Sharon
1 solutions
Answer 209612 by richwmiller(9144) on 2010-04-06 22:02:04 (Show Source):
You can put this solution on YOUR website!sum means we are going to add things
less means we are subtracting something
is means equals
twice means two times
difference means subtraction
x+y=-15+2x
or
x+y=2x-15
Now the second sentence
x-y=-5+2x
or
x-y=2x-5
#1
x+y=2x-15
#2
x-y=2x-5
combine
y=x-15
-y=x-5
add
0=2x-20
20=2x
x=10
10-5=-y
5=-y
y=-5
(10,-5)
#1
x+y=2x-15
10-5=20-15
5=5
#2
x-y=2x-5
10-(-5)=2*(10)-5
15=20-5
15=15
ok
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Graphs/289397: What is the x-coordinate of the solution to the system of linear equations below?
4x + 5y = 8
2x - 3y = -18
is this right? 2x + 2y = 10
troykoen@gmail.com
1 solutions
Answer 209610 by richwmiller(9144) on 2010-04-06 21:50:46 (Show Source):
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logarithm/289247: I am trying to solve this exponent equation: 3^2-x^2=8 the whole exponent is 2-x^2. I have the answer of + or - .3274, but would like to see the solution outlined. Thank you.
1 solutions
Answer 209606 by richwmiller(9144) on 2010-04-06 21:33:21 (Show Source):
You can put this solution on YOUR website!I think the other tutor misread the problem.
3^(2-x^2)=8
3^2*3^(-x^2)=8
9*3^(-x^2)=8
1/(3^(x^2))=8/9
3^(x^2)=9/8
x=-sqrt((log(9/8))/(log(3)))
x=-0.327431
x=sqrt((log(9/8))/(log(3)))
x=0.327431
= your answer
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Miscellaneous_Word_Problems/289380: at work one day erica received 36 packages. Speedy delivery delivered three times as many as ralphs express, While ralphs express delivered four more packages the sendquick package service. how many packages did each service deliver to erica?
1 solutions
Answer 209602 by richwmiller(9144) on 2010-04-06 21:09:48 (Show Source):
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Exponents/289325: Hey guys.
Recently in a maths textbook I read something along the lines of (xy)^3 (can't figure out how to write it so that it comes up like a power, sorry). The answer, much to my disbelief, the answer was xy^3 (as I understand it should have been x^3y^3). I wrote it off as an error in the answering sheet (something that happens somewhat often) and moved on. Now, however, I've come to an example further in the book of a question written:
{(ab)^2}^-4
it then continues:
(ab^2)^-4 = a^-4 b^2*-4
= a^-4 b^-8
= 1/(a^4b^8)
This is confusing me beyond comprehension; how is {(ab)^2}^-4 equal to (ab^2)^-4? Is it equal, or have they made yet another stuff up? Normally I'd think my previous teacher taught me wrong faced with so much evidence, but I simply can't find any consistency, everything in the brackets is raised to the -4, why not the 2? Combined with the fact that this book has had three things in a row wrong before, I'm inclined to believe who ever wrote it was either tired or drunk.
My thanks;
Matt.
1 solutions
Answer 209601 by richwmiller(9144) on 2010-04-06 21:00:29 (Show Source):
You can put this solution on YOUR website!Were these gaffs in the answer section in the back of the book?
Textbooks are famous for changing the problems but not changing the answers.
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Finance/289364: I am needing help solving this word problem- these are too confusing to me
The total profit (in dollars) for sales of x rowing machines is given by P(x)= -0.2^2 + 300x -200. What is the profit if 500 are sold? For what value of x will the profit be a at maximum?
Thanks,
Jen
1 solutions
Answer 209595 by richwmiller(9144) on 2010-04-06 20:27:39 (Show Source):
You can put this solution on YOUR website!Check you equation. There is something missing.
Probably an x in the term -0.2^2 It should probably be -0.2x^2
Otherwise it is a straight line.
so when you get the right equation, you should find the vertex.
-b/2a
here b is 300
a=-.2
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Linear-equations/289360: Provide 3 coordinate points that would lie on the line x=7. Explain in your own words what the line x=7 would look like if it were graphed, and explain how do you know?
1 solutions
Answer 209593 by richwmiller(9144) on 2010-04-06 20:22:58 (Show Source):
You can put this solution on YOUR website!x=7 is a vertical line.
Y changes but x never changes.
So just pick any three numbers for y and match them up with
(7, )
(7, )
(7, )
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Linear-equations/289350: I'm not sure how to do this one... I'm sure there's a certain "formula" but I don't know it.
Write an equation for the line parallel to the line 4x=-3 through the point (4,-3).
1 solutions
Answer 209592 by richwmiller(9144) on 2010-04-06 20:20:10 (Show Source):
You can put this solution on YOUR website!Actually, it is easier than you think. You just have to know stuff.
4x=-3 is a vertical line
So your equation will be of the form x=?
We want the line to pass through 4,-3
So x=4 y=-3
And the equation is
x=4
All done
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Rate-of-work-word-problems/289349: You are the parent of busy children and have a parent teacher conference in one hour; you know that it takes 10 minutes for the cold water to fill the tub and 12 minutes for the hot water to fill the tub. How long will it take to fill the tub if both faucets are open
1 solutions
Answer 209590 by richwmiller(9144) on 2010-04-06 20:13:13 (Show Source):
You can put this solution on YOUR website!x/10+x/12=1
12x+10x=120
22x=120
11x=60
x=60/11=5 5/11 minutes
5*60/11
300/11=27 second
5 minutes and 27 seconds together
check
60/11/10=6/11 for the cold water
60/11/12=5/11 for the hot water
6/11+5/11=1
ok
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Linear-systems/289238: Dear Professor,
i would very much appreciate it if you could help me solve the following algebra problem.
thanks
solve the system of equations,using substitiution or eliminationor back-substitution etc.
x+3y-z=13
2x -5z=23
4x-y-2z=4
1 solutions
Answer 209569 by richwmiller(9144) on 2010-04-06 16:54:16 (Show Source):
You can put this solution on YOUR website!x = -12/17, y = 50/17, z = -83/17
x+3y-z=13
2x -5z=23
4x-y-2z=4
multiply the first by -2
-2x-6y+2z=-26
4x-y-2z=4
add
2x-7y=-22
multiply #1 by 5
5x+15y-5z=65
2x -5z=23
subtract
3x+15y=42
divide by 3
x+5y=14
2x-7y=-22
#1 by 2
2x+10y=28
2x-7y=-22
subtract
17y=50
y=50/17
2x-7y=-22
2x-7*50/17=-22
x-7*25/17=-11
x=-12/17
2x -5z=23
2*(-12/17)-5z=23
-24/17-5z=23*17/17
z=-83/17
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Circles/289235: A baseball has the radius of 1.5". Home plate is 16 inches wide. If the baseball rolled across home plate, how many complete rotations would it take to cover the distance?
1 solutions
Answer 209565 by richwmiller(9144) on 2010-04-06 16:40:49 (Show Source):
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Finance/289228: at 7:00 a.m joe starts jogging at 6 mi/h. at 7:30 ken starts off after him. how fast must ken run in order to overtake him at 7:30 a.m.?
1 solutions
Answer 209563 by richwmiller(9144) on 2010-04-06 16:36:11 (Show Source):
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