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Recent problems solved by 'mathslover'

mathslover answered: 135 problems
Jump to solutions: 0..29 , 30..59 , 60..89 , 90..119 , 120..149, >>Next

Numbers_Word_Problems/613992: In a group of 38, an election was held from captain.There were two candiates. If Alex beat Chris by 14 votes, then the number of votes that colin got was...
1 solutions

Answer 386350 by mathslover(135) About Me  on 2012-05-23 04:17:44 (Show Source):
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>>If Alex beat Chris by 14 votes, then the number of votes that colin got was
Probably you meant the number of votes Chris got and not Colin...
Assumption : everyone voted.
Assume Chris got x votes,
Since Alex beat Chris by 14 votes, which means he got 14 votes more
ie x+14

Total votes= total number of people
x+x+14=38
=>2x+14=38
=>2x=24
=>x=12
Chris got 12 votes and alex got 26 votes (12+14)


Geometry_Word_Problems/613984: to make 8 flags it takes 6 meters of cloth. how many meters would you need to make 20 flags
1 solutions

Answer 386348 by mathslover(135) About Me  on 2012-05-23 03:49:26 (Show Source):
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To make 8 flags it requires 6 meters of cloth
=> to make 1 flag it requires 6/8 meters of cloth
=> to make 20 flags it would require %286%2F8%29+%2A+20 of cloth
=120/8
=15 meters of cloth


Linear_Equations_And_Systems_Word_Problems/613980: the difference of squares of two numbers is 88.If the larger number is 5 less than twicw the smaller one ,then find the two nubers?

1 solutions

Answer 386346 by mathslover(135) About Me  on 2012-05-23 03:36:35 (Show Source):
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Let the smaller number be x
Now the larger number = 5 less thann 2 times the smaller number
= 2x -5
Difference of the sqaures of the 2 numbers is 88
%282x-5%29%5E2+-+x%5E2=88
=>4x%5E2+-20x+%2B+25+-x%5E2=88
=>3x%5E2+-+20x+-+63=0 Grouping the common terms together
=>x=+%28-%28-20%29%2B-+sqrt%28400+-+4%2A3%2A+-63%29%29%2F%282%2A3%29
=>x=+%2820%2B-+sqrt%28400%2B756%29%29%2F6
=>x=%2820%2B-sqrt%281256%29%29%2F6
=>x=%2820%2B%2834%29%29%2F6+and x=%2820-%2834%29%29%2F6++
=>x=54%2F6+and x=+-14%2F6
=>x=9+and+x=-7%2F3
Therefore the smaller number is 9 and the bigger number is 2*9-5= 13
Ignoring the negative -7/3 as 2 times this number - 5 that is (-14/3 -5 =-29/5),gives a smaller number and not a larger number as in the problem statement


Angles/330199: if the degree measures of 2 comlementary angles are in the ratio 2:13, what is the measure of the smaller angle?
1 solutions

Answer 236642 by mathslover(135) About Me  on 2010-08-09 12:29:15 (Show Source):
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Sum of the complementary angles is 90 degress.
If one of the angles is 2x , the other angle is 13x
(from the given condition that their ratios are 2:13)
=> 2x + 13x = 90
=> 15x = 90
=> x=6
Measure of the smaller angle is 2x = 2* 6 =12 degrees


Travel_Word_Problems/330147: Professor Ortiz leaves campus on her bike, heading west at 6mph. Professor Wilson leaves campus at the same time and walk south at 2.5mph. how far apart are they after 4hrs? include check

1 solutions

Answer 236625 by mathslover(135) About Me  on 2010-08-09 11:05:25 (Show Source):
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In 4 Hours , Prof Ortiz would have travelled 4* 6 = 24 miles west
In 4 Hours ,Wilson would have travelled 4* 2.5 = 10 miles south
B
|
|
|
0--------A

The distance between them is the distance AB as depicted in the figure.
Note that they form 2 sides of a right angled triangle.
Using the Pyathogrean theorem,
AB%5E2+=+OA%5E2++%2B+OB%5E2
AB%5E2+=+24%5E2+%2B+10%5E2
AB%5E2+=+576+%2B+100
AB%5E2+=+676
AB+=+sqrt%28676%29
AB=+26


Triangles/330002: The base of a traingle is 1/3 as long as its height. If the area is 24 square meters, how long is its base?
1 solutions

Answer 236492 by mathslover(135) About Me  on 2010-08-08 20:56:38 (Show Source):
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Let the height be x
So the base is x/3 (One third of the height )
Area of a triangle
=1/2 * base * height
According to the given condition
1/2 * x/3 * x = 24
x^2/6 = 24
Multiplying both sides by 6
x^2 = 24*6
x^2=144
x=sqrt(144)
therefore x=12
and x/3 = 4
Base is 4 and height is 12


Quadratic-relations-and-conic-sections/329976: Prove that tan x (cot x + tan x) = sec^2x
1 solutions

Answer 236484 by mathslover(135) About Me  on 2010-08-08 20:32:31 (Show Source):
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Prove that tan x (cot x + tan x) = sec^2x
LHS (Left hand side)
tan x (cot x + tan x)
=tan x * cot x + (tan x)(tan x)
=1+ tan^2 x
=1 + sin^2 x/cos ^ x
=(cos ^ 2 x + sin ^ x)/cos ^2 x
=1/cos^2 x
=sec ^2 x = RHS (right hand side)


real-numbers/330001: Simplify "(5 + 3i)(5 - 3i)." Is the result real, complex, or both? Explain.
1 solutions

Answer 236482 by mathslover(135) About Me  on 2010-08-08 20:24:34 (Show Source):
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Simplify "(5 + 3i)(5 - 3i)." Is the result real, complex, or both?
Note the expression is of the form (A+B)(A-B)= A^2 - B^2
therefore we can write
5 + 3i)(5 - 3i)
as 5^2 - (3i)^2
=25 - 9i^2
=25 -9(-1) as i^2 = -1
=25+9
=34 which is real number.


Polynomials-and-rational-expressions/324557: factor completely (x+3)^2-10(x+3)+24

write a quadratic equation and answer the following: the shortest leg of a right triangle is two less than the hypotenuse. the hypotenuse is one longer than the longest leg.
thank you
1 solutions

Answer 232292 by mathslover(135) About Me  on 2010-07-21 22:25:01 (Show Source):
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(x+3)^2-10(x+3)+24
Let's replace x+3 by A
So, the given expression would transform to
A^2 -10A + 24
Rewriting it as
A^2 - 6A -4A + 24
A(A-6) -4(A-6)
Taking A-6 as the common factor,
(A-6)(A-4)
Substituting A=x+3 back into the expression we get
(x+3-6)(x+3-4)
(x-3)(x-1) is the required factor.
==========================================================================
write a quadratic equation and answer the following: the shortest leg of a right triangle is two less than the hypotenuse. the hypotenuse is one longer than the longest leg.
Let the longest leg be x
So the hypotenuse is (x+1) {the hypotenuse is one longer than the longest leg}
And the shortest leg is (x+1)-2=x-1 {the shortest leg of a right triangle is two
less than the hypotenuse}
Using Pythagoras's theorem,
hypotenuse^2 = shorter leg^2 + longer leg^2
we get
(x+1)^2 = (x-1)^2 + x^2
Expanding the LHS and the RHS
x^2 + 2x+ 1 = x^2 -2x+1 + x^2
Moving the Right hand side expression to Left hand side we get
x^2 + 2x+ 1 - (x^2 -2x+1 + x^2)= 0
grouping the like terms,
(x^2 - x^2 -x^2) + (2x + 2x ) + (1 -1)=0
-x^2 + 4x =0
-x(x-4)=0
which gives x=0 and x=4 as two possible solutions. But we cannot have a triangle with side of length 0. So discarding x=0 we get the other solution as x=4
Hence, the sides of the triangle are
The longest side=4
The shorter side=4-1=3
hypotenuse=4+1=5


Numbers_Word_Problems/140068: Choose three consecutive odd integers such that three times the second decreased by 4 is equal to twice the third increased by 15. Answers (choose one): (a) 11, 13, 15 (b) 13, 15, 17 (c) 23, 25, 27 (d) 25, 27, 29. I don't get how to do this at all. What is "consecutive" anyways? Thanks.
1 solutions

Answer 102077 by mathslover(135) About Me  on 2008-05-05 01:14:38 (Show Source):
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What is "consecutive" anyways?
By consecutive we mean appearing one after the other. So for example 1,3,5 are consecutive odd integers.Again 7,9,11 are similarly 3 consecutive odd integers.
Now to the solution of the actual problem.
Let the three integers
be x,x+2,(x+2)+2 Notice in the example above how they differ by 2.
i.e. x,x+2 and x+ 4 are the 3 consecutive odd integers.
Given
3%2A%28x%2B2%29+-4+ = 2+%2A%28x%2B4%29+%2B+15
3x%2B+6+-4=2x+%2B+8+%2B15
3x+%2B+2 =2x+%2B+23
Group the like terms
3x+-+2x+ = 23+-2
x=21
therefore the other 2 numbers are 23 and 25
Numbers are 21,23,25

Verify
3%2A23+-+4+=+25%2A2+%2B15
69+-4+=+50+%2B+15
65+=+65+


Percentage-and-ratio-word-problems/140063: On Monday, Popeye ate a third of a new case of spinach. On Tuesday, he ate 75% of what remained in the case after Mondays meal. On Wednesday, he finished the case. Tuesday's meal consisted of 12 cans of spinach. How much spinach did he eat on Monday? Show how you know?
Ohhh, I am so frustrated with this problem. Is this something I have to work backwards on? Please helo me. Thankyou dani..
1 solutions

Answer 102076 by mathslover(135) About Me  on 2008-05-05 00:54:54 (Show Source):
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Let the total spinach cans in the case be x
On Monday he ate 1%2F3+%2Ax+ of the spinach cans.
So amount left after Monday = x+-+x%2F3
=+%283x+-x%29%2F3
=2x/3
On Tuesday he ate 75% of the remaining
i.e. %2875%2F100%29+%2A+%282x%2F3%29
Given that on Tuesday he at 12 cans. Therefore,
%2875%2F100%29+%2A+%282x%2F3%29 =12
%283%2F4%29+%2A+%282x%2F3%29= 12 simplifying 75/100 as 3/4
x%2F2= 12
x=+12%2A2
x=24
The amount he ate on Monday = x/3
= 24/3
= 8 cans


Probability-and-statistics/140064: There are two spinners. The first spinner is a circle that is cut in fours. the numbers read 10, 12, 14, 18. The other spinner is also cut in fours and the numbers are 1, 2, 3, 4
Ok.. The two spinners shown are spun and the difference between the results is found. Find the probability that the difference is a multiple of 3.
Thankyou.. Danielle, AKA Dani
1 solutions

Answer 102075 by mathslover(135) About Me  on 2008-05-05 00:39:55 (Show Source):
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The total different outcomes of the two spinners are
4* 4= 16
The outcomes are (10,1),(10,2),(10,3),(10,4),(12,1),(12,2),(12,3),(12,4),(14,1),
(14,2),(14,2),(14,3),(18,1),(18,2),(18,3),(18,4)

Out of these pairs, the ones for which the difference is multiple of 3 are:
(10,1), difference 9
(10,4) difference 6
(12,3) difference 9
(14,2) difference 12
(18,3) difference 15
So the required probability = favorable outcomes/ total outcome
= 5/16


Inequalities/98512: Hello out there,I really need some help with some problems,the first one is Solve the inequality:[2x]<8.The next one is,Solve the inequality:[p+2]<6.The third is,Solve the inequality:Solve the inequality:[z+3]>2.And the last one is,Which of the points satisfy y-3<2x? (0,0)or(1,5)or(-2,0).Thanks for anyone that can help.
1 solutions

Answer 71675 by mathslover(135) About Me  on 2007-09-16 14:14:16 (Show Source):
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Before giving out the solution to the problem here is something you should
know
[x] means the greatest integer value less than or equal to x
so for e.g [1.2] = 1
[-5.6] = -6
[4]=4
now to the questions
1. [2x] < 8
2[x] < 8 (Note [2x] is not = 2[x] but [2x] <= 2[x] so without loss of inequality we can write [2x] as 2[x]) in the above inequality
[x]< 4

for all x < 4, [x] <4
hence solution set for the above is x< 4
2. [ p + 2] <6
for all p+2 < 6 , [p+2] will be less than 6
p < 4
3 [z +3 ] >2
since [z+3] is an integer value [z+3] should be >=3 ( integer greater than 2)
which gives z>=0
4.y-3<2x? (0,0)or(1,5)or(-2,0).
substitue x=0, y=0
0-3< 2*0
-3 <0 hence it satisfies the equation
Substituting x=1 , y=5
5-3 < 2*1
2< 2
It does not satisfy the equation
Substituting x= -2 , y=0
0 - 3 < 2* -2
-3 < -4
it does not satisfy the equation
The only point satisfying the equation is (0,0)







Equations/98458: Using the digits 1-9 in order, insert operation signs and grouping symbols to get the value of 100. you can only use a number once.Help Me. Please...
1 solutions

Answer 71632 by mathslover(135) About Me  on 2007-09-15 23:05:34 (Show Source):
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(1 * 2 * ( 3 + 4 ) * 5 ) + 6 + 7 + 8 + 9 =100

verification:
(2 * 7 * 5 ) + 6+7+8 +9
70 + 30 =100


Mixture_Word_Problems/98457: This question is from textbook Algebra and Trigonometry
Please help me with this mixture word problem. A jewel has five rings, each weighing 18 g, made of an alloy of 10% silver and 90% gold. He decides to melt down the rings and add enough silver to reduce the gold content to 75%. How much silver should he add? I'm having a lot of difficulty with setting up and equation for this particular problem. I would be very thankful if you would help me out. Thank you
1 solutions

Answer 71631 by mathslover(135) About Me  on 2007-09-15 22:53:33 (Show Source):
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total weight of the rings = 18 * 5 = 90g
total amount of silver = 10/100 *90 = 9g
Total amount of gold in all the 5 rings = 90 -9 =81g
Let the amount of silver added be x grams
total weight of the mixture now = 90 + x
percentage of gold = 81/(90+x) *100
since the percentage of gold now is to be 75
81/(90+x) *100 = 75
81 * 100 = 75 (90+x)
27 * (3 * 25) * 4= 75(90+x)
canceling out 75 on both sided
27* 4 = 90 +x
x = 108 -90
=18g


Polynomials-and-rational-expressions/98446: factor monomials from polynomials
3(x+2)(x-4)+6(x+2)(x+1)
1 solutions

Answer 71630 by mathslover(135) About Me  on 2007-09-15 22:19:36 (Show Source):
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3(x+2)(x-4)+6(x+2)(x+1)
=3(x+2)[((x-4 + 2(x+1)]
=3(x+2)( x-4 + 2x +2)
=3(x+2)(3x -2)


Graphs/98454: find the slope of the line passing through (3,4) and (3,-4)
1 solutions

Answer 71627 by mathslover(135) About Me  on 2007-09-15 21:51:33 (Show Source):
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Slope = %28y2+-y1%29%2F%28x2+-x1%29
= +%28-4+-4%29%2F%283+-+3+%29
= infinity
which means that the line is perpendicular to the x-axis
equation of the line is x=3


expressions/98456: Insert parentheses to make each pair of expressions equal.
3*8+6squared-8/2=26
1 solutions

Answer 71625 by mathslover(135) About Me  on 2007-09-15 21:46:42 (Show Source):
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3*8+6squared-8/2=26
%28%283%2A8%29+%2B+%286%5E2+-+8+%29%29%2F2+=26
+%2824+%2B+%2836+-8%29+%29%2F2+=26
+%2824+%2B+28%29%2F2+=26+
%2852%2F2%29+=26
26+=26+ which is true ..does it make sense now
((3*8) + (6^2 - 8 ))/2 =26


Graphs/98455: what are the solutions for x-y=4
1 solutions

Answer 71623 by mathslover(135) About Me  on 2007-09-15 21:42:33 (Show Source):
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Since there are 2 variables in the equation x-y=4 , you need at least 2 equations to find the values of x and y


Length-and-distance/98450: the distance between the points (4,-3)and (x,3) is 10. find X

i am coming up with +12 the answer should be -4,
Thanks
1 solutions

Answer 71619 by mathslover(135) About Me  on 2007-09-15 21:29:28 (Show Source):
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Use the distance formula
D = +sqrt+%28+%28x2+-x1%29%5E2+%2B+%28y2+-y1%29%5E2+%29
10 = +sqrt+%28+%28x+-4%29%5E2+%2B+%283+-%28-3%29%29%5E2+%29
square on both sides
100+=+%28x-4%29%5E2+%2B+36+
+%28x-4%29%5E2+=+100+-36
%28x-4%29%5E2+=64
x-4 = +-8
x=12 and x=-4
So your answer of 12 is also correct


Quadratic_Equations/98447: Most quadratic eqautions Ive come across so far have given the problem as something equals 0 format. This one below is the first Ive seen in this format so its got me scratching my head.
Use the quadratic equation to solve: 6n^2= -8n-1
Give the answer in decimal form.
This neither has the equals 0 as a start point or ask me what to solve for. It just says solve. Help please.
Thank you.
1 solutions

Answer 71616 by mathslover(135) About Me  on 2007-09-15 21:20:53 (Show Source):
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Given equation
6n^2= -8n-1
add 8n +1 on both sides
6n^2 + 8n + 1 =0 ( looks more familiar now ?)
use the quadratic formula
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
n=+%28-8+%2B-+sqrt%288%5E2+-+4%2A6%2A1%29%29%2F%282%2A6%29
n=+%28-8+%2B-+sqrt%2864+-+24%29%29%2F12
n=+%28-8+%2B-+sqrt%2840%29%29%2F12
n=+%28-8+%2B-+6.325+%29%2F12%29
n= -1.193 and n= -0.1396


real-numbers/98448: This question is from textbook Advanced Algebra 1.5 word problems
2. a bag of lawn fertilizer claims that it will cover 5,000 square feet of grass. If your yard is 27,500 square feet, how many bags of fertilizer will you need?
1 solutions

Answer 71614 by mathslover(135) About Me  on 2007-09-15 21:09:34 (Show Source):
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number of bags required = 27,500/5,000
= 5.5 bags


Systems-of-equations/98445: This question is from textbook elementary and intermediate algebra
the sum ot three numbers is 105. the third is 11 less than ten times the second. twice the first is 7 more than three times the second. find the numbers.
my work so far:
a+b+c=105
10b=c+11 >> 10b-c=1
2a=7+3b >> 2a-3b=7
next i know i have to get rid of one of the numbers so i decided on "a" and i started with equations 1 and 3 so i multiplyed 1 by 2 so the "a"s would cancel out.
-2a-2b-c=105
+
2a-3b=7
-5b-c=112
but now im stuck i dont know what to do next.

1 solutions

Answer 71613 by mathslover(135) About Me  on 2007-09-15 21:05:52 (Show Source):
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Let the second number be x
from the problem statement "the third is 11 less than ten times the second"
third number = 10x -11
again from the problem statement "first is 7 more than three times the second"
first number = 3x + 7
Sum of the numbers =105
3x+7 + x + 10x-11 =105
14x = 109
x= 109/14
second number is 109/14
first number = 10* 109/14 -11
=936/14
third number = 3* 109/14 + 7
=425/14


Geometry_proofs/98310: NEED HELP WITH PROOF:
A PROOF HAS THE FOLLOWING STEPS:
1.
2.
3. MEASURE OF ANGLE K + MEASURE OF ANGLE J = MEASURE OF ANGLE P + MEASURE OF ANGLE 1.
4. MEASURE OF ANGLE A = MEASURE OF ANGLE K + MEASURE OF ANGLE J
5. MEASURE OF ANGLE F = MEASURE OF ANGLE P + MEASURE OF ANGLE 1.
6. MEASURE OF ANGLE A = MEASURE OF ANGLE F.
THE QUESTION ASKS WHAT THE REASON IS FOR STEP 6?
A. SYMMETRIC PROPERTY OF EQUALITY
B. SUBSTITUTION PROPERTY OF EQUALITY
C. ANGLE ADDITION POSTULATE
D. REFLEXIVE PROPERTY OF EQUALITY
THANKS IN ADVANCE!!! PLEASE GIVE ME THE ANSWER AND WHY IT IS THE ANSWER!!!!
:)
1 solutions

Answer 71612 by mathslover(135) About Me  on 2007-09-15 20:51:31 (Show Source):
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3. MEASURE OF ANGLE K +MEASURE OF ANGLE J=MEASURE OF ANGLE P + MEASURE OF ANGLE 1.
4. MEASURE OF ANGLE A = MEASURE OF ANGLE K + MEASURE OF ANGLE J
5. MEASURE OF ANGLE F = MEASURE OF ANGLE P + MEASURE OF ANGLE 1.
6. MEASURE OF ANGLE A = MEASURE OF ANGLE F.
THE QUESTION ASKS WHAT THE REASON IS FOR STEP 6?
A. SYMMETRIC PROPERTY OF EQUALITY
B. SUBSTITUTION PROPERTY OF EQUALITY
C. ANGLE ADDITION POSTULATE
D. REFLEXIVE PROPERTY OF EQUALITY
the answer is B. Substitution property of equality
Reason
from the statements
3. MEASURE OF ANGLE K +MEASURE OF ANGLE J=MEASURE OF ANGLE P + MEASURE OF ANGLE 1.
4. MEASURE OF ANGLE A = MEASURE OF ANGLE K + MEASURE OF ANGLE J
we have by substituting MEASURE OF ANGLE K + MEASURE OF ANGLE J=MEASURE OF A IN
in 3
MEASURE OF ANGLE A = MEASURE OF ANGLE P + MEASURE OF ANGLE 1.
Now statement 5
5. MEASURE OF ANGLE F = MEASURE OF ANGLE P + MEASURE OF ANGLE 1.
Substituting MEASURE OF ANGLE P + MEASURE OF ANGLE 1 as MEASURE OF ANGLE F in the statement above
MEASURE OF ANGLE A = MEASURE OF ANGLE F which is statement 6


Number-Line/98444: what number is one-third the way between 3 and 5.
1 solutions

Answer 71611 by mathslover(135) About Me  on 2007-09-15 20:37:53 (Show Source):
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the number which is one-third between 3 and 5 is
= (3+5)/3
=11/3 or 3 2/3


Percentage-and-ratio-word-problems/98439: the number of usa triathlon member grew from 16,000 in 1993 to 40,000 in 2002. Calculate the percentage by which the number increased.
1 solutions

Answer 71610 by mathslover(135) About Me  on 2007-09-15 20:32:53 (Show Source):
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Increase in members = 40,000 - 16,000
=24,000
percentage increase = (increase in members/ initial members )*100
= (24,000/40,000)*100
=60%
Answer : the members grew by 60%


percentage/98443: How much would I have left after taking 25% out of 3,181 dollars? I have been trying to figure it out and I'm having a heck of a time.
1 solutions

Answer 71609 by mathslover(135) About Me  on 2007-09-15 20:26:49 (Show Source):
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after taking 25% what you are left with is 75% of 3181 dollars
Amount left =75/100 * $3181
=$2385.75


Rational-functions/98442: WHICH OF THESE ARE IRRATIONAL NUMBERS 17/3,SQUARE ROOT OF 11, -1.82, OR 5.3WITH A LINE OVER THREE?
1 solutions

Answer 71607 by mathslover(135) About Me  on 2007-09-15 20:23:51 (Show Source):
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Any number which cannot be expressed in the form a/b where b not equal to zero is a irrational number
the given numbers are
17/3 since its in the form of a/b with b!=0 hence rational
-1.82 = -182/100 again can be expressed in the form of a/b where b!=0
sqrt%2811%29 cannot be expressed in the form of a/b and is IRRATIONAL
5.3/3 = 53/10 can be expressed as a/b and is rational


Expressions-with-variables/98408: 5x + 8 + 3x - x + 5 = 6x - 3
1 solutions

Answer 71572 by mathslover(135) About Me  on 2007-09-15 16:26:04 (Show Source):
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The given equation is :
5x + 8 + 3x - x + 5 = 6x - 3
the way to solve such equations is first to group all the variable terms (here x) at one side and the constants on the other.
So we have :
5x + 3x - x - 6x = -8 - 5 - 3
x = -16


Graphs/98403: The credit remaining on a phone card (in dollars) is a linear function of the total calling time made with the card (in minutes), as shown in the figure below. The remaining credit after 23 minutes of calls is $21.78 , and the remaining credit after 57 minutes of calls is $17.02 . What is the remaining credit after 87 minutes of calls?

1 solutions

Answer 71568 by mathslover(135) About Me  on 2007-09-15 16:17:04 (Show Source):
You can put this solution on YOUR website!
let the total credit C after M minutes of call be given by
C = $(a*M + b) where a and b are some constants.
So we have:
21.78 = a * 23 + b (1) and
17.02 = a * 57 + b (2)
Subtracting equation (2) from (1):
4.76 = -34a
a = -4.76/34
= -.14
Putting this value of a in equation (1):
21.78 = -.14 * 23 + b
therefore, b = 21.78 + 3.22
= 25
So the linear equation for the credit remaining after M minutes of call is
C = $(-.14 * M + 25)
So, the remaining credit after 87 minutes
C = -.14 * 87 + 25
= $12.82


Complex_Numbers/98339: This question is from textbook college algebra
How do I solve: (3+square root -5)(7-square root -10)?
1 solutions

Answer 71511 by mathslover(135) About Me  on 2007-09-15 10:56:50 (Show Source):