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Answer 404309 by jim_thompson5910(28476) on 2012-08-29 16:05:54 (Show Source):
You can put this solution on YOUR website!If the positive number is larger than the negative value (ignore the negative sign), then
positive + negative = positive
ex:
5 plus -2 = 3, which is positive
Notice how 5 is larger than 2
-------------------------------------------------------
If the positive number is smaller than the negative value (ignore the negative sign), then
positive + negative = negative
ex:
3 plus -12 = -9, which is negative
Notice how 3 is smaller than 12
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Graphs/643012: problem 8Y-7=-7
8Y-7+7=-7+7
8y=0
I entered no solution
I think I worked it right. 1 solutions
Answer 404298 by jim_thompson5910(28476) on 2012-08-29 15:19:33 (Show Source):
You can put this solution on YOUR website! Start with the given equation.
 Add  to both sides.
 Combine like terms on the right side.
 Divide both sides by  to isolate  .
 Reduce.
----------------------------------------------------------------------
Answer:
So the solution is
Note: a solution of zero is still a solution, so the answer is NOT "no solution".
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Equations/643008: Read and answer each.
1. Is 30 a perfect number? explain your answer.
2.Is 21 a prime number? Is 43 a prime number?Explain.
3.Give an example of a composite number and tell why it is a composite number.
4.Is 48 a multiple of 6? Is 8 a multiple of 40? Explain.
5. Is 8 a factor of 20? Is 7 a factor of 35? Explain. 1 solutions
Answer 404297 by jim_thompson5910(28476) on 2012-08-29 15:14:19 (Show Source):
You can put this solution on YOUR website!1. Is 30 a perfect number? explain your answer.
No, 30 doesn't equal the sum of its factors.
--------------------------------------------------------------------------
2.Is 21 a prime number? Is 43 a prime number?Explain.
No, 21 = 7*3 which means it's not prime. The number 43 is prime since its only factors are 1 and 43.
--------------------------------------------------------------------------
3.Give an example of a composite number and tell why it is a composite number.
27 is a composite number since 27 = 3*9, so it can be factored into the product of two smaller numbers (none of which are 1 or 27)
--------------------------------------------------------------------------
4.Is 48 a multiple of 6? Is 8 a multiple of 40? Explain.
48 is a multiple of 6 since 48 = 6*8. The number 8 is NOT a multiple of 40 since 8 = 40x has NO integer solution.
--------------------------------------------------------------------------
5. Is 8 a factor of 20? Is 7 a factor of 35? Explain.
8 is NOT a factor of 20 since 8x = 20 has no integer solution
7 is a factor of 35 since 35 = 7*5
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Equations/642930: 4/5y-4=-9/10y+1 1 solutions
Answer 404279 by jim_thompson5910(28476) on 2012-08-29 12:21:12 (Show Source):
You can put this solution on YOUR website! Start with the given equation.
 Multiply both sides by the LCD  to clear any fractions.
 Distribute and multiply.
 Add  to both sides.
 Add  to both sides.
 Combine like terms on the left side.
 Combine like terms on the right side.
 Divide both sides by  to isolate  .
----------------------------------------------------------------------
Answer:
So the solution is
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Functions/642926: Is the relation {(1,3),(-4,0),(3,1),(0,4),(2,3)} a function? Why or why not? 1 solutions
Answer 404278 by jim_thompson5910(28476) on 2012-08-29 12:20:12 (Show Source):
You can put this solution on YOUR website!Since each x value maps to one and ONLY ONE y value, this means that this given relation is indeed a function.
If we had x = 2 mapping to both y = 3 and y = 4 at the same time, then this wouldn't be a function (since this x value is mapping to more than one y value). But that's not the case here.
So again, this relation is a function.
===============================================================================
Summary
Is the relation {(1,3),(-4,0),(3,1),(0,4),(2,3)} a function? Yes
Why or why not? See explanation above
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Permutations/642859: There are 15 ‘True or False’ questions in an examination. In how many ways can a student do the examination if he or she can also choose not to answer almost 3 questions? 1 solutions
Answer 404275 by jim_thompson5910(28476) on 2012-08-29 11:59:24 (Show Source):
You can put this solution on YOUR website!If the student answers all 15 questions, then there is only one way to do this.
-------------------------------------------------------
If the student skips one question, and exactly one question only, then there are 15 ways to do this (since there are 15 questions to skip).
-------------------------------------------------------
If the student skips two questions, then there are 15 C 2 = 15*14/2 = 105 ways to do this.
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If the student skips three questions, then there are 15 C 3 = 15*14*13/6 = 455 ways to do this.
=======================================================
So if a student can skip at most 3 questions, then there are 1+15+105+455 = 576 different ways to do this.
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Sequences-and-series/642819: Cn=(-1)^n(n-17)^2 What are the first three terms? 1 solutions
Answer 404273 by jim_thompson5910(28476) on 2012-08-29 11:38:35 (Show Source):
You can put this solution on YOUR website!The 1st term is
Cn = (-1)^n(n-17)^2
C1 = (-1)^1(1-17)^2
C1 = (-1)^1(-16)^2
C1 = (-1)(256)
C1 = -256
--------------------------------------------
The 2nd term is
Cn = (-1)^n(n-17)^2
C2 = (-1)^2(2-17)^2
C2 = (-1)^2(-15)^2
C2 = (1)(225)
C2 = 225
--------------------------------------------
The 3rd term is
Cn = (-1)^n(n-17)^2
C3 = (-1)^3(3-17)^2
C3 = (-1)^3(-14)^2
C3 = (-1)(196)
C3 = -196
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Permutations/642890: a product code is made from 3 non-distinct letters from this set { W,Y,T,U,X,R}.
how many different codes contain exactly 1 R? 1 solutions
Answer 404270 by jim_thompson5910(28476) on 2012-08-29 11:31:08 (Show Source):
You can put this solution on YOUR website!If repetition is NOT allowed (ex: RTX is allowed, but RTT is NOT allowed)
Case 1) First letter is R
There are 6 letters total. After picking R, you have 5 left. So there are 5*4 = 20 ways to arrange the remaining letters in the remaining two slots.
Case 2) Second letter is R
Same as case 1, but now the R is in the second slot instead of the first. There are still 5 letters left and 5*4 = 20 ways to arrange these 5 remaining letters in the two outer slots.
Case 3) Third letter is R
Same as case 1, but now R is in slot 3. So there are 20 ways to arrange the remaining letters.
So we have 3 cases with 20 ways each giving us 3*20 = 60 ways total.
===========================================================================
OR
If repetition is allowed (ex: RTT is finally allowed), then...
You have 6 letters, but you can only have exactly one R. So once you choose that R (for say the first slot), then you have 5 letters left to choose from for the second slot. Since repetition is allowed, you also have 5 letters left to choose for the 3rd slot.
So you have 5*5 = 25 ways to choose an R for the first slot, then 2 (maybe repeating) letters for the second and third slot.
This can be generalized if R was in any slot. So there are 3 times as many ways, which means that there are 3*25 = 75 different ways
=========================================================================
Summary:
So again, if repetition is NOT allowed, then there are 60 ways to do this.
If repetition is allowed, then there are 75 ways to do this.
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Inequalities/642694: 6x-4+3/2x=5x+11
I have put x all on one side 6x+3/2x-5x=11+4
I made everything with x an fraction 12/2x+3/2x-10/2x=15
12+3-5=10
10/2=5
5x=15
x=3 1 solutions
Answer 404190 by jim_thompson5910(28476) on 2012-08-28 21:44:53 (Show Source):
You can put this solution on YOUR website!You made a mistake in red below
12+3 -5=10
when it *should* be
12+3-10 = 5
which becomes 5/2
So
12/2x+3/2x-10/2x=15
5/2x=15
5x = 15*2
5x = 30
x = 30/5
x = 6
So the solution is x = 6
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Radicals/642667: How do you solve 7(1 − x) = 9(1 + 2x) + 8.
7-7x=9+18x+8
7-7x=17+18x
7-7-7x=17-7+18x
7x=10+18x
7x-18x=10+18x-18x
-11x=10
1 solutions
Answer 404178 by jim_thompson5910(28476) on 2012-08-28 21:19:58 (Show Source):
You can put this solution on YOUR website!You made a mistake highlighted in red
7-7x=9+18x+8
7-7x=17+18x
7-7-7x=17-7+18x
7x=10+18x
7x-18x=10+18x-18x
-11x=10
It should be -7x and not 7x. So you lost a negative sign somehow.
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 Start with the given equation.
 Distribute.
 Combine like terms on the right side.
 Subtract  from both sides.
 Subtract  from both sides.
 Combine like terms on the left side.
 Combine like terms on the right side.
 Divide both sides by  to isolate  .
 Reduce.
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Answer:
So the solution is
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Angles/642660: I need to find the measure of the third angle and they give me this:
x°, (123 – x)°
how can i do it? 1 solutions
Answer 404175 by jim_thompson5910(28476) on 2012-08-28 21:11:03 (Show Source):
You can put this solution on YOUR website!Let y = third missing angle
Since the three angles (in any triangle) must add to 180, we know that
x+(123-x) + y = 180
123 + y = 180
y = 180 - 123
y = 57
So the third angle is 57 degrees
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Geometry_proofs/642658: The question is:
Can you think of any way to prove from Euclid's postulates that for every line l
(a) There exists a point lying on l?
(b) There exists a point not lying on l?
I'm thinking it has something to do with Euclid's parallel postulate, but I'm not sure. I have never written proofs before, so I am just having a difficult time trying to formulate this properly. Any help would be appreciated. Thank you! 1 solutions
Answer 404173 by jim_thompson5910(28476) on 2012-08-28 21:08:01 (Show Source):
You can put this solution on YOUR website!a)
Any line is uniquely determined by 2 points. So if you have a line, then you know it has at least two points on it.
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b)
Parallel lines will NEVER intersect in euclidean geometry (in the plane). This means that parallel lines will not have any points in common. So the existence of parallel lines shows us that if you have a line, then there are points that do not lie on this given line (since these points will lie on the parallel lines).
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expressions/642612: T - 7 for t = 20
Is the answer 13?
2 xsquared for x = 3
Is the answer 18?
The word for is throwing me off 1 solutions
Answer 404156 by jim_thompson5910(28476) on 2012-08-28 20:15:18 (Show Source):
You can put this solution on YOUR website!t - 7
20 - 7
13
So you are correct.
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2x^2
2(3)^2
2(9)
18
So you are correct on both
Note: T - 7 for t = 20 can be reworded to say "find t - 7 when t = 20"
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Exponents/642610: Square the binomial
(7x-9)^2
1 solutions
Answer 404153 by jim_thompson5910(28476) on 2012-08-28 20:10:42 (Show Source):
You can put this solution on YOUR website!
 Start with the given expression.
 Expand. Remember something like  .
Now let's FOIL the expression.
Remember, when you FOIL an expression, you follow this procedure:
 Multiply the First terms:  .
 Multiply the Outer terms:  .
 Multiply the Inner terms:  .
 Multiply the Last terms:  .
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So we have the terms:  ,  ,  ,
 Now add every term listed above to make a single expression.
 Now combine like terms.
So  FOILs to  .
In other words,  for all values of x.
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Jim
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