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Answer 205165 by richwmiller(9132) on 2010-03-18 17:28:55 (Show Source):
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Quadratic_Equations/282540: i need help and a couple of things explained better if possible
this is what my textbook says:
By drawing a suitable graph, find the roots of these quadratic functions. Check each root by substitution:
this is what we have been told to find by our teacher
where does x²-x=0 cut the y-intercept
where it cuts the x-axis
locate the turning point (an axis of symmetry)
i dont know how to do any of it so there is nothing i can write to show what i have done so far ?
thanks if you get back to me x 1 solutions
Answer 205163 by richwmiller(9132) on 2010-03-18 17:24:23 (Show Source):
You can put this solution on YOUR website!There are some problems with your wording.
x^2-x=0
x*(x-1)=0
the two roots are x=0 and x=1
that is where the parabola crosses the x axis
(0,0) and (1,0)
x intercept is when y =zero the zeroes or roots of the equation
y intercept is when x=0
Nothing cuts the y intercept. Perhaps you want to know the y intercept where x=0 or where it cuts(crosses) the y axis.
1/2^2-1/2
1/4-1/2=-1/4
| Solved by pluggable solver: SOLVE quadratic equation with variable |
Quadratic equation (in our case ) has the following solutons:

For these solutions to exist, the discriminant should not be a negative number.
First, we need to compute the discriminant : .
Discriminant d=1 is greater than zero. That means that there are two solutions: .


Quadratic expression can be factored:

Again, the answer is: 1, 0.
Here's your graph:
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Linear-equations/282548:
4.
The equation a = 640s gives the relationship between s square miles and a acres. Pam owns 7.5 square miles of farmland. How many acres does she own? 1 solutions
Answer 205153 by richwmiller(9132) on 2010-03-18 17:09:00 (Show Source):
You can put this solution on YOUR website!some website rules
one problem per submission
no similar problems
max 4 submissions daily
a=640s
plug in 7.5 for s
a=640*7.5
and calculate acres
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Linear-equations/282430: I have a question and i dont have a clue how to do it so would love some help if possible.
Find the equation of this line with y-intercept=-1 and passing through (-1;-2)
Would Love Helppppp 1 solutions
Answer 205064 by richwmiller(9132) on 2010-03-18 11:44:12 (Show Source):
You can put this solution on YOUR website!see this problem and 3 solutions
http://www.algebra.com/algebra/homework/Linear-equations/Linear-equations.faq.question.282417.html
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Geometry_Word_Problems/281882: The radius of a circular flower garden is 4 meters. How many meters of edging will be needed to surround the garden?
A) 7.14 meters B) 12.56 meters C)25.12 meters D)50.27 meters E)3.14 meters
1 solutions
Answer 205061 by richwmiller(9132) on 2010-03-18 11:36:51 (Show Source):
You can put this solution on YOUR website!c=2 pi r
c=2*3.14*4
c=8*3.14
We can approximate 8*3=24 the only answer even close is 25.12
since "none of the above' is not a choice it must be 25.12.
and yes 3.14*8=25.12
if you didn't know that 8*14 is 112 you should know that 8*7=56 and 2*56=112
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Quadratic_Equations/282422: Solve using the five-step problem-solving process. Show all steps necessary to arrive at your solution.
The product of two consecutive positive integers is 272. Find the integers. 1 solutions
Answer 205058 by richwmiller(9132) on 2010-03-18 11:28:39 (Show Source):
You can put this solution on YOUR website!x*(x+1)=272
x^2+x-272=0
16 and 17
| Solved by pluggable solver: Factoring using the AC method (Factor by Grouping) |
In order to factor , first multiply the leading coefficient 1 and the last term -272 to get -272. Now we need to ask ourselves: What two numbers multiply to -272 and add to 1? Lets find out by listing all of the possible factors of -272
Factors:
1,2,4,8,16,17,34,68,136,272,
-1,-2,-4,-8,-16,-17,-34,-68,-136,-272, List the negative factors as well. This will allow us to find all possible combinations
These factors pair up to multiply to -272.
(-1)*(272)=-272
(-2)*(136)=-272
(-4)*(68)=-272
(-8)*(34)=-272
(-16)*(17)=-272
Now which of these pairs add to 1? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to 1
| First Number | | | Second Number | | | Sum | | 1 | | | -272 | || | 1+(-272)=-271 | | 2 | | | -136 | || | 2+(-136)=-134 | | 4 | | | -68 | || | 4+(-68)=-64 | | 8 | | | -34 | || | 8+(-34)=-26 | | 16 | | | -17 | || | 16+(-17)=-1 | | -1 | | | 272 | || | (-1)+272=271 | | -2 | | | 136 | || | (-2)+136=134 | | -4 | | | 68 | || | (-4)+68=64 | | -8 | | | 34 | || | (-8)+34=26 | | -16 | | | 17 | || | (-16)+17=1 |
We can see from the table that -16 and 17 add to 1. So the two numbers that multiply to -272 and add to 1 are: -16 and 17
So the original quadratic

breaks down to this (just replace with the two numbers that multiply to -272 and add to 1, which are: -16 and 17)
Replace with 
Group the first two terms together and the last two terms together like this:

Factor a 1x out of the first group and factor a 17 out of the second group.

Now since we have a common term we can combine the two terms.
Combine like terms.
==============================================================================
Answer:
So the quadratic factors to 
Notice how foils back to our original problem . This verifies our answer. | |
| Solved by pluggable solver: SOLVE quadratic equation with variable |
Quadratic equation (in our case ) has the following solutons:

For these solutions to exist, the discriminant should not be a negative number.
First, we need to compute the discriminant : .
Discriminant d=1089 is greater than zero. That means that there are two solutions: .


Quadratic expression can be factored:

Again, the answer is: 16, -17.
Here's your graph:
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Linear-equations/282417: My Teacher has been of for ages and came in the other day to give us a homework sheet but the thing is we havent learnt any of this stuff so have looked everywhere on the internet for examples but cant find any so thought i would try this site.
The question is:
Find the equation of this line with the y-intercept=2 and passing through (2;6)
Would love if you could help with this question as i find it easier to work out the following questions if i can see how one was done first :) Thanks Youu 1 solutions
Answer 205054 by richwmiller(9132) on 2010-03-18 11:13:16 (Show Source):
You can put this solution on YOUR website!You seem to know that we are dealing with linear equations.
Have you heard of y=mx+b?
m is the slope and b is the y intercept?
Have you heard of this to find slope?
(y-y)/(x-x)=m
So we know two points.
(2,6) and (0,2)
Where did I get (0,2)? the y intercept 2 is when x=0. That means (0,2)
(y-y)/(x-x)=m
6-2/2-0=4/2=2 slope is 2
plug in the new info slope =2 and old info y intercept=2
y=mx+b
y=2x+2
done
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decimal-numbers/282412: how do i figure out this simple problem?
25 divided by .5? 1 solutions
Answer 205047 by richwmiller(9132) on 2010-03-18 10:51:51 (Show Source):
You can put this solution on YOUR website!There are many ways
1-we could use a calculator
2- 25/.5= 250/5=50
We could change .5 to 1/2
3-25/1/2=25*2=50
Remember multiplying by the reciprocal is the same as dividing by the number.
The reciprocal of 1/2 is 2
So dividing by 1/2 is the same as multiplying by 2
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Quadratic_Equations/282408: Factor completely. Remember to look first for a common factor. Check by multiplying. If a polynomial is prime, state this.
27m^2 - 36 + 12
This is what I have got so far if I am heading in the right direction please let me know and what I do next if not help me figure this one out.
27m^2 - 36 + 12
=3(9x^2 - 12x + 4)
=3[(3x)^2 - 4*3 + 2^2]
That's all I got so far. 1 solutions
Answer 205046 by richwmiller(9132) on 2010-03-18 10:46:18 (Show Source):
You can put this solution on YOUR website!first i suspect that you copied the problem incorrectly
27m^2 - 36 + 12
I suspect it should be
27m^2 - 36m + 12
You perform some magic with the equation changing m's to x's
and then the last line is completely a mystery what you are doing and why you are doing it.
assuming it should be
27m^2 - 36m + 12
3*(9m^2-12m+4)
| Solved by pluggable solver: Factoring using the AC method (Factor by Grouping) |
In order to factor , first multiply the leading coefficient 9 and the last term 4 to get 36. Now we need to ask ourselves: What two numbers multiply to 36 and add to -12? Lets find out by listing all of the possible factors of 36
Factors:
1,2,3,4,6,9,12,18,36,
-1,-2,-3,-4,-6,-9,-12,-18,-36, List the negative factors as well. This will allow us to find all possible combinations
These factors pair up to multiply to 36.
1*36=36
2*18=36
3*12=36
4*9=36
6*6=36
(-1)*(-36)=36
(-2)*(-18)=36
(-3)*(-12)=36
(-4)*(-9)=36
(-6)*(-6)=36
note: remember two negative numbers multiplied together make a positive number
Now which of these pairs add to -12? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to -12
| First Number | | | Second Number | | | Sum | | 1 | | | 36 | || | 1+36=37 | | 2 | | | 18 | || | 2+18=20 | | 3 | | | 12 | || | 3+12=15 | | 4 | | | 9 | || | 4+9=13 | | 6 | | | 6 | || | 6+6=12 | | -1 | | | -36 | || | -1+(-36)=-37 | | -2 | | | -18 | || | -2+(-18)=-20 | | -3 | | | -12 | || | -3+(-12)=-15 | | -4 | | | -9 | || | -4+(-9)=-13 | | -6 | | | -6 | || | -6+(-6)=-12 |
We can see from the table that -6 and -6 add to -12. So the two numbers that multiply to 36 and add to -12 are: -6 and -6
So the original quadratic

breaks down to this (just replace with the two numbers that multiply to 36 and add to -12, which are: -6 and -6)
Replace with 
Group the first two terms together and the last two terms together like this:

Factor a 3m out of the first group and factor a -2 out of the second group.

Now since we have a common term we can combine the two terms.
Combine like terms.
==============================================================================
Answer:
So the quadratic factors to 
which can also be written as since the factors repeat themselves
Notice how foils back to our original problem . This verifies our answer. | |
| Solved by pluggable solver: Factoring using the AC method (Factor by Grouping) |
In order to factor , first multiply the leading coefficient 27 and the last term 12 to get 324. Now we need to ask ourselves: What two numbers multiply to 324 and add to -36? Lets find out by listing all of the possible factors of 324
Factors:
1,2,3,4,6,9,12,18,27,36,54,81,108,162,324,
-1,-2,-3,-4,-6,-9,-12,-18,-27,-36,-54,-81,-108,-162,-324, List the negative factors as well. This will allow us to find all possible combinations
These factors pair up to multiply to 324.
1*324=324
2*162=324
3*108=324
4*81=324
6*54=324
9*36=324
12*27=324
18*18=324
(-1)*(-324)=324
(-2)*(-162)=324
(-3)*(-108)=324
(-4)*(-81)=324
(-6)*(-54)=324
(-9)*(-36)=324
(-12)*(-27)=324
(-18)*(-18)=324
note: remember two negative numbers multiplied together make a positive number
Now which of these pairs add to -36? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to -36
| First Number | | | Second Number | | | Sum | | 1 | | | 324 | || | 1+324=325 | | 2 | | | 162 | || | 2+162=164 | | 3 | | | 108 | || | 3+108=111 | | 4 | | | 81 | || | 4+81=85 | | 6 | | | 54 | || | 6+54=60 | | 9 | | | 36 | || | 9+36=45 | | 12 | | | 27 | || | 12+27=39 | | 18 | | | 18 | || | 18+18=36 | | -1 | | | -324 | || | -1+(-324)=-325 | | -2 | | | -162 | || | -2+(-162)=-164 | | -3 | | | -108 | || | -3+(-108)=-111 | | -4 | | | -81 | || | -4+(-81)=-85 | | -6 | | | -54 | || | -6+(-54)=-60 | | -9 | | | -36 | || | -9+(-36)=-45 | | -12 | | | -27 | || | -12+(-27)=-39 | | -18 | | | -18 | || | -18+(-18)=-36 |
We can see from the table that -18 and -18 add to -36. So the two numbers that multiply to 324 and add to -36 are: -18 and -18
So the original quadratic

breaks down to this (just replace with the two numbers that multiply to 324 and add to -36, which are: -18 and -18)
Replace with 
Group the first two terms together and the last two terms together like this:

Factor a 9m out of the first group and factor a -6 out of the second group.

Now since we have a common term we can combine the two terms.
Combine like terms.
==============================================================================
Answer:
So the quadratic factors to 
Notice how foils back to our original problem . This verifies our answer. | |
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Finance/282402: Please help, returning back to school after 30 yrs and it's hard to grasp
$2.28 each and the cookies at $1.19 each. How much total revenue would result from selling all the scones and cookies baked in the oven at one time?c. Yesterday your store earned $797.30 just from the sale of cookies. Write and solve an equation that represents how many cookies were sold.
1 solutions
Answer 205043 by richwmiller(9132) on 2010-03-18 10:19:35 (Show Source):
You can put this solution on YOUR website!your first problem is missing the first part.
some website rules you may not like.
One problem per submission
no similar problems
limit 4 submissions daily
I assume the 2.28 is for scones and the 1.19 is for cookies
1.19x=797.30
x=670 cookies
The rest of the problem is missing.
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Numeric_Fractions/282396: I am trying to understand how to divide fractions.
can you help me with this problem?
2/4 divided by 1/5=
thank you 1 solutions
Answer 205036 by richwmiller(9132) on 2010-03-18 10:02:43 (Show Source):
You can put this solution on YOUR website!let's look at some examples first and see what we notice.
if we divide 20 by 5 we get 4
20/5=4 but 20 *1/5 also equals 4
so dividing by a number is the same as if we multiply by the reciprocal
so if we divide by 1/5 we can also multiply by 5
if we divide by 5 we can multiply by 1/5
2/4 divided by 1/5 is the same as multiplying by 5
2/4*5=10/4
BTW 2/4 -1/2
so 1/2*5=10/4=2.5 or 2 1/2
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Numeric_Fractions/282360: This is the problem and they want an algebra solution.
Three tired and hungry men went to sleep with a bag of apples. One man woke up, ate 1/3 of the apples, then went back to sleep. Later a second man woke up and ate 1/3 of the remaining apples, then went back to sleep.Finally,the third man woke and ate 1/3 of the remaining apples. When he was finished there were 8 apples left. How many apples were in the bag originally? 1 solutions
Answer 205028 by richwmiller(9132) on 2010-03-18 09:38:13 (Show Source):
You can put this solution on YOUR website!This problem appears every couple weeks.
x-x/3-1/3(x-x/3)-1/3(x-x/3-1/3(x-x/3))=8
x=27
first guy ate 1/3*27=9 leaving 18
next guy ate 18/3=6 leaving 12
3rd guy at 12/3=4 leaving 8
A simpler way to calculate by working backwards
2/3x=8
x=12
2/3x=12
x=18
2/3x=18
x=27
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Travel_Word_Problems/282361: The time required to drive from Duluth to Fargo varies inversely with the speed of the car. If the trip takes 6.25 hours at 40 mph, what speed is required to make the trip in 4 hours?
A) 6.4 mph B) 0.625 mph C) 25.6 mph D) 8.44 mph E) 62.5 mph
1 solutions
Answer 205024 by richwmiller(9132) on 2010-03-18 09:26:49 (Show Source):
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Triangles/282383: the measure of each three angles of a triangle are represented by x,2x,and x+60, find the numerical measure of each angle
1 solutions
Answer 205022 by richwmiller(9132) on 2010-03-18 09:22:50 (Show Source):
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Average/282382: What is the average?
A total of 50 juniors and seniors were given a math test. The 35 juniors attained an average score of 80 while the 15 seniors attained an average of 70. What is the average score for all 50 students who took the test?
1 solutions
Answer 205020 by richwmiller(9132) on 2010-03-18 09:19:16 (Show Source):
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Linear-systems/282366: You can rent a mid size car from Company A for $250 per week with unlimited mileage. A similar car can be rented from Company B for $150 per week plus 25 cents for each mile driven. How many miles must you drive in a week in order for the rental fee for Company B to be equal to that for Company A?
A) 330 miles B) 150 miles C) 160miles D) 400 miles E) None of the above.
1 solutions
Answer 205019 by richwmiller(9132) on 2010-03-18 09:17:06 (Show Source):
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Polynomials-and-rational-expressions/282331: Please solve this problem and show the steps in solving it. 12y^2 - 5y = 2. 1 solutions
Answer 205016 by richwmiller(9132) on 2010-03-18 09:08:12 (Show Source):
You can put this solution on YOUR website!
| Solved by pluggable solver: Factoring using the AC method (Factor by Grouping) |
In order to factor , first multiply the leading coefficient 12 and the last term -2 to get -24. Now we need to ask ourselves: What two numbers multiply to -24 and add to -5? Lets find out by listing all of the possible factors of -24
Factors:
1,2,3,4,6,8,12,24,
-1,-2,-3,-4,-6,-8,-12,-24, List the negative factors as well. This will allow us to find all possible combinations
These factors pair up to multiply to -24.
(-1)*(24)=-24
(-2)*(12)=-24
(-3)*(8)=-24
(-4)*(6)=-24
Now which of these pairs add to -5? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to -5
| First Number | | | Second Number | | | Sum | | 1 | | | -24 | || | 1+(-24)=-23 | | 2 | | | -12 | || | 2+(-12)=-10 | | 3 | | | -8 | || | 3+(-8)=-5 | | 4 | | | -6 | || | 4+(-6)=-2 | | -1 | | | 24 | || | (-1)+24=23 | | -2 | | | 12 | || | (-2)+12=10 | | -3 | | | 8 | || | (-3)+8=5 | | -4 | | | 6 | || | (-4)+6=2 |
We can see from the table that 3 and -8 add to -5. So the two numbers that multiply to -24 and add to -5 are: 3 and -8
So the original quadratic

breaks down to this (just replace with the two numbers that multiply to -24 and add to -5, which are: 3 and -8)
Replace with 
Group the first two terms together and the last two terms together like this:

Factor a 3y out of the first group and factor a -2 out of the second group.

Now since we have a common term we can combine the two terms.
Combine like terms.
==============================================================================
Answer:
So the quadratic factors to 
Notice how foils back to our original problem . This verifies our answer. | |
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