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Maths68 answered: 1474 problems
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5 decreased by the product of a number and 3?
The sum of -9 times a number and 6 is 72?
Thank-you for your consideration if you have time to answer my question. 1 solutions
Answer 417262 by Maths68(1474) on 2012-10-24 00:18:55 (Show Source):
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Equations/637959: Half the sum of two numbers is 20 and three times their difference is 18. Find the numbers 1 solutions
Answer 401956 by Maths68(1474) on 2012-08-16 12:55:49 (Show Source):
You can put this solution on YOUR website!Let
Smaller Number = x
Larger Number = y
Half the sum of two numbers is 20
(x+y)/2=20
x+y=2*20
x+y=40...............(1)
Three times their difference is 18
3(y-x)=18
3(y-x)/3=18/3
y-x=6..............(2)
Add (1) and (2)
x+y=40...............(1)
y-x=6..............(2)
---------------------
2y=46
2y/2=46/2
y=23
Put the value of y in (1)
x+y=40...............(1)
x+23=40
x=40-23
x=17
Smaller Number = x = 17
Larger Number = y = 23
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Age_Word_Problems/637635: How old are Edz and Noe now, if Edz is twice as old as Noe and the sum of their ages is 66? ITS MY QUIZ. PLEASE ANSWER :) 1 solutions
Answer 401824 by Maths68(1474) on 2012-08-15 12:50:41 (Show Source):
You can put this solution on YOUR website!Let
Edz present age = e
Noe present age = n
Edz is twice as old as Noe
e=2n..............(1)
The sum of their ages is 66
e+n=66............(2)
Put the value of e in (2)
2n+n=66
3n=66
3n/3=66/3
n=22
Put the value of n in (1)
e=2n..............(1)
e=2(22)
e=44
Edz present age = e = 44
Noe present age = n = 22
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Travel_Word_Problems/637387: The sum of the speeds of two trains is 723.7. If the speed of the first train is 10.3 faster than the second train, find the speeds of each.
HELP!! this is killing me that i cant figure this out 1 solutions
Answer 401633 by Maths68(1474) on 2012-08-14 13:05:15 (Show Source):
You can put this solution on YOUR website!Let
Speed of slower train = x
Speed of faster train = x+10.3
Speed of slower train + Speed of faster train = Sum of speeds
x+x+10.3=723.7
2x+10.3=723.7
2x=723.7-10.3
2x=713.4
2x/2=713.4/2
x=356.7
Speed of slower train = x = 356.7
Speed of faster train = x+10.3 = 356.7+10.3=367
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Travel_Word_Problems/637089: Keiko runs 7 miles in 80 mins. At the same rate, how many miles would she run in 32mins? 1 solutions
Answer 401418 by Maths68(1474) on 2012-08-13 13:59:56 (Show Source):
You can put this solution on YOUR website!In 80 mins...............7 miles
In 80/80 mins............7/80 miles
In 1 mins............7/80 miles
In (32)*1 mins.........(7/80)*(32)miles
In 32 mins.........(7/80)(32)miles
In 32 mins.........(7/5)(2)miles
In 32 mins.........14/5miles
In 32 mins.........2.8miles
Or
In 1 minute keiko runs = 7/80 = 0.0875 miles
In 32 minutes keiko run = 0.875*32 = 2.8 miles
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Miscellaneous_Word_Problems/637069: In the following sum the same two numbers are needed. When they are added or mutliplied together, they form the answers for (a) and (b). I need to work out what theose numbers are
(a) ............+........... = 2.7
(b) ............x........... = 1.8
Can anone help me with the following I just cnat seem to get it thanks
I have already submitted this question but my email address was wrong 1 solutions
Answer 401416 by Maths68(1474) on 2012-08-13 13:50:30 (Show Source):
You can put this solution on YOUR website!Let x and y be the two numbers
x+y=2.7
x+y=27/10
10(x+y)=27
10x+10y=27.............(1)
xy=1.8
xy=18/10
x=18/10y...............(2)
Put the value of x from (2) to (1)
10(18/10y)+10y=27
18/y+10y=27
(18+10Y^2)/y=27
18+10Y^2=27y
10y^2-27y+18=0
| 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=9 is greater than zero. That means that there are two solutions: .


Quadratic expression can be factored:

Again, the answer is: 1.5, 1.2.
Here's your graph:
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So
y=1.5 or 1.2
Put the values of y in (1)
10x+10y=27.............(1)
Put y=1.5
10x+10(1.5)=27
10x+15=27
10x=27-15
10x=12
x=12/10
x=1.2
Put the values of y in (1)
10x+10y=27.............(1)
Put y=1.2
10x+10(1.2)=27
10x+12=27
10x=27-12
10x=15
x=15/10
x=1.5
So numbers are 1.2 and 1.5
Check
=====
xy=1.8
(1.2)(1.5)=1.8
1.8=1.8
x+y=2.7
1.2+1.5=2.7
2.7=2.7
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Age_Word_Problems/636780: Two years hence, John's mother will be twice his age.Five years hence his father will be thrice his present age.What is the difference between the ages of his parents,if the sum of all the three ages is 105? 1 solutions
Answer 401243 by Maths68(1474) on 2012-08-12 13:47:10 (Show Source):
You can put this solution on YOUR website!Let
Present age of mother = m years old
Present age of father = f years old
Present age of John = j years old
Two years hence
mother will be = m+2 years old
John will be = j+2 years old
Then
mother will be twice his age
m+2=2(j+2)
m+2=2j+4
m=2j+4-2
m=2j+2.................(1)
Five years hence
father will be = f+5 years old
John will be = j+5 years old
Then
father will be thrice his present age
f+5=3(j+5)
f+5=3j+15
f=3j+15-5
f=3j+10..................(2)
the sum of all the three ages is 105
m+j+f=105
Put the value of m and f from (1) and (2) to above equation
2j+2+j+3j+10=105
6j+12=105
6j=105-12
6j=93
6j/6=93/6
j=31/2
Put the value of j in (1)
m=2j+2.................(1)
m=2(31/2)+2
m=31+2
m=33
Put the value of j in (2)
f=3j+10..................(2)
f=3(31/2)+10
f=93/2+10
f=(93+20)/2
f=113/2
f=56.5
Difference b/w parents ages = f-m=56.5-33= 23.5 years.
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Money_Word_Problems/636786: Lauren paid for movie tickets which cost $8.50 for adults and $4.75 for students. She ordered six times as many student tickets as adult tickets. The total cost is $111. How many student tickets did she purchase? 1 solutions
Answer 401236 by Maths68(1474) on 2012-08-12 13:19:39 (Show Source):
You can put this solution on YOUR website!Lauren Purchased adult tickets = x
Lauren Purchased student tickets = 6x
Cost of a Adult ticket = 8.50
Cost of a student ticket = 4.75
Total Cost of all tickets = 111
(Lauren Purchased adult tickets)(Cost of a Adult ticket)+(Lauren Purchased student tickets)(Cost of a student ticket) = Total Cost of all tickets
(x)(8.50)+(6x)(4.75)=111
8.50x+28.50=111
37x=111
37x/37=111/37
x=3
Lauren Purchased adults tickets = x = 3
Lauren Purchased students tickets = 6x = 6*3 = 18
Check
======
Total Cost of Adults tickets = 8.50*3=25.50
Total Cost of students tickets= 4.75*18=85.50
Total Cost = 25.5+85.5=111
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Linear-equations/636427: Find the slope‐intercept equation of the line with the following properties: Parallel to the line y= 6; containing the point (5,7) 1 solutions
Answer 401046 by Maths68(1474) on 2012-08-11 02:34:00 (Show Source):
You can put this solution on YOUR website!Equation of the line slope-intercept form
y=mx+b
Given
Equation of the Given line
y=6
Compare with the equation of line slope-intercept form
Slope of the given = m = 0
Since lines are parallel their slope will be same
Slope of the required line = m = 0
Point (5, 7)
We have a point and slope we can get easily the require line equation.
Use Equation of the line point-slope form
m = y2-y1/x2-x1
Put the values in above equation, we have
m=(y-2)/(x-5)
0(x-5)=(y-7)
0=y-7
y=7
Above equation is the equation of the required line
Graph
======
y=6
y=7
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Age_Word_Problems/636450: Paul is 11 years younger than Wendy. In 10 years, Wendy will be twice as old as Paul. How old is Paul now? 1 solutions
Answer 401045 by Maths68(1474) on 2012-08-11 02:21:41 (Show Source):
You can put this solution on YOUR website!Let
Present age of Paul = p years old
Present age of Wendy = w years old
Paul is 11 years younger than Wendy.
w=p+11............(1)
In 10 years,
Paul will be = p+10 years old
Wendy will be = w+10 years old
Then
Wendy will be twice as old as Paul
w+10=2(p+10)
w+10=2p+20
w=2p+20-10
w=2p+10................(2)
Put the value of w from (1) to (2)
p+11=2p+10
p-2p=10-11
-p=-1
p=1
Put the value of p in (1)
w=p+11............(1)
w=1+11
w=12
Present age of Paul = p = 1 year old
Present age of Wendy = w = 12 years old
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Mixture_Word_Problems/636474: How much of a 5% cream and a 0.5% cream would be required to compound 75 g of a 2% cream?
1 solutions
Answer 401037 by Maths68(1474) on 2012-08-11 01:03:00 (Show Source):
You can put this solution on YOUR website!Cream A
=======
Amount = x
Cream = 5%=0.05
Cream B
=======
Amount = 75-x
Cream = 0.5%=0.005
Mixture Cream
=============
Amount = 75g
Cream = 2%=0.02
(Amount)(cream A)+(Amount)(Cream B)= (Amount)(Mixture Cream)
0.05x+(75-x)0.005=(75)(0.02)
0.05x+(75-x)0.005=(0.02)(75)
0.05x+(75-x)0.005=1.5
0.05x+0.375-0.005x=1.5
0.045x+0.375=1.5
0.045x=1.5-0.375
0.045x=1.125
0.045x/0.045=1.125/0.045
x=25
Cream A
=======
Amount = x = 25g
Cream = 5%=0.05
Cream B
=======
Amount = 75-x=75-25=50g
Cream = 0.5%=0.005
Mixture Cream
=============
Amount = 75g
Cream = 2%=0.02
25g of a 5% cream and 50g of a 0.5% cream would be required to compound 75 g of a 2% cream.
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Mixture_Word_Problems/636461: How much 20% antifreeze solution must be mixed with a 80% antifreeze solution to produce 30 gallons of a 60% disinfectant solution? 1 solutions
Answer 401035 by Maths68(1474) on 2012-08-11 00:43:58 (Show Source):
You can put this solution on YOUR website!Solution A
===========
Amount = x gallons
Concentration = 20%=0.2
Solution B
===========
Amount = 30-x gallons
Concentration = 80%=0.8
Mixture
=======
Amount = 30 gallons
Concentration = 60% = 0.6
(Amount of Solution A)(Concentration of Solution A)+(Amount of Solution B)(Concentration of Solution B)=(Amount of Mixture)(Concentration of Mixture)
(x)(0.2)+(30-x)(0.8)=(30)(0.6)
0.2x+24-0.8x=18
0.2x-0.8x=18-24
-0.6x=-6
-0.6x/-0.6=-6/-0.6
x=10
10 gallon of 20% antifreeze solution must be mixed with 20 gallons of 80% antifreeze solution to produce 30 gallons of a 60% disinfectant solution.
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Mixture_Word_Problems/636254: A solution of 61% bleach is to be mixed with a solution of 27% bleach to make 68 gallons of a 44% solution. How many gallons of each should be used?
1 solutions
Answer 400964 by Maths68(1474) on 2012-08-10 14:13:18 (Show Source):
You can put this solution on YOUR website!Solution A
===========
Amount = x gallons
Concentration = 61%=0.61
Solution B
===========
Amount = 68-x
Concentration = 27%=0.27
Mixture
=======
Amount = 68 gallons
Concentration = 44% = 0.44
(Amount of Solution A)(Concentration of Solution A)+(Amount of Solution B)(Concentration of Solution B)=(Amount of Mixture)(Concentration of Mixture)
(x)(0.61)+(68-x)(0.27)=(68)(0.44)
0.61x+18.36-0.27x=29.92
0.34x+18.36=29.92
0.34x=29.92-18.36
0.34x=11.56
0.34x/0.34=11.56/0.34
x=34
Solution A
===========
Amount = x = 34 gallons
Concentration = 61%=0.61
Solution B
===========
Amount = 68-x = = 68-34 = 34 gallons
Concentration = 27%=0.27
Mixture
=======
Amount = 68 gallons
Concentration = 44% = 0.44
34 gallons of each should be used.
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Rectangles/636311: A rectangle 15cmx30cm is increased on all sides by the same amount. It's area is increased by 144cm^2. By how much is each dimension increased? 1 solutions
Answer 400960 by Maths68(1474) on 2012-08-10 13:59:00 (Show Source):
You can put this solution on YOUR website!Let
Increase on all sides = x
Area of rectangle = length * width
A=L*W
A=15*30
A=450
After Increase
A=450+144
A=594
Length = 30+x
Width = 15+x
594=(15+x)(30+x)
594=450+15x+30x+4x^2
594=450+45x+x^2
594-450=45x+x^2
144=45x+x^2
x^2+45x-144=0
x^2+48x-3x-144=0
x(x+48)-3(x+48)=0
(x-3)(x+48)=0
x-3=0 or x+48=0
x=3 or x=-48 (unacceptable)
x=3
Each dimension increased by 3cm
Length = 30+x = 30+3 = 33cm
Width = 15+x = 15+3 = 18cm
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Age_Word_Problems/636356: the sum of julies age and her fathers age is 58. if julies father is 10 years younger than triple Julie's age, find their age. 1 solutions
Answer 400940 by Maths68(1474) on 2012-08-10 13:08:32 (Show Source):
You can put this solution on YOUR website!Let
Present age of Julies = j years old
Present age of Father = f years old
the sum of julies age and her fathers age is 58
j+f=58
j=58-f.............(1)
julies father is 10 years younger than triple Julie's age
3j=f-10............(2)
Put the value of j from (1) to (2)
3j=f-10
3(58-f)=f-10
174-3f=f-10
-3f-f=-10-174
-4f=-164
-4f/-4=-164/-4
f=41
Put the value of f in (1)
j=58-f.............(1)
j=58-41
j=17
Present age of Julies = j = 17 years old
Present age of Father = f = 41 years old
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Age_Word_Problems/635687: the square of katie's age six year ago is equal to her age in six years time. find her present age 1 solutions
Answer 400668 by Maths68(1474) on 2012-08-09 03:52:07 (Show Source):
You can put this solution on YOUR website!Let
Present age of Katie = k years old
Six years ago
Katie was = k-6 years old
In Six years
Katie will be = k+6 years old
The square of katie's age six year ago is equal to her age in six years time
(k-6)^2=k+6
k^2-12k+36=k+6
k^2-13k+30=0
Solve for K
k^2-10k-3k+30=0
k(k-10)-3(k-10)=0
(k-3)(k-10)=0
k-3=0 or k-10=0
k=3 (unacceptable) or k=10
k=10
Present age of Katie = k = 10 years old
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Percentage-and-ratio-word-problems/635955: A part-time instructor is receiving $950 per
credit taught. If the instructor receives a 4% increase,
how much will the new per credit compensation be 1 solutions
Answer 400665 by Maths68(1474) on 2012-08-09 02:42:08 (Show Source):
You can put this solution on YOUR website!New Per credit compensation = Old compensation + increase%
New Per credit compensation = 950+(950)(4/100)
New Per credit compensation = 950+(950)(1/25)
New Per credit compensation = 950+38
New Per credit compensation = 988
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Expressions-with-variables/635945: 8 y - 1 = x
3 x = 2 y
I need to find x and y. I'm stuck on it, thanks in advance. 1 solutions
Answer 400646 by Maths68(1474) on 2012-08-09 00:36:13 (Show Source):
You can put this solution on YOUR website!8y-1=x..............(1)
3x=2y...............(2)
Substitute the value of x from (1) to (2)
3(8y-1)=2y
24y-3=2y
24y-2y=3
22y=3
22y/22=3/22
y=3/22
Put the value of y in (2)
3x=2(3/22)
3x=3/11
3x/3=(3/11)/3
x=1/11
x,y=1/11,3/22
Check
=====
Put the values of x and y in (1)
8y-1=x..............(1)
8(3/22)-1=1/11
24/22-1=1/11
(24-22)/22=1/11
2/22=1/11

Put the values of x and y in (1)
3x=2y...............(2)
3(1/11)=2(3/22)
3/11=6/22
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Miscellaneous_Word_Problems/635919: tickets to the local circus cost 3 dollars for children and 5 dollars for adult. There were 3 times as many children tickets sold as adult tickets. All together the circus made 700 dollars. How many children and how many adult bought tickets to the circus? 1 solutions
Answer 400641 by Maths68(1474) on 2012-08-08 23:50:36 (Show Source):
You can put this solution on YOUR website!Adults tickets sold = x
Children tickets sold= 3x
Total Amount = $700
(Cost of a children ticket)(Children tickets sold)+(Cost of an adult ticket)( Adult tickets sold)= Total Amount
3(3x)+5(x)=700
9x+5x=700
14x=700
14x/14=700/14
x=50
Adults tickets sold = x = 50
Children tickets sold= 3x = 3*50 = 150
Check
=====
3*150+5*50=700
450+250=700
700=700
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Age_Word_Problems/635677: a father is now 3 times as old as his son. twelve years ago, he was six times as old as his son. find the present age of each 1 solutions
Answer 400481 by Maths68(1474) on 2012-08-08 03:32:10 (Show Source):
You can put this solution on YOUR website!Let
Present age of of Father = f years old
Present age of Son = s years old
Father is 3 times as old as his son
f=3s...............(1)
12 years ago
father was = f-12 years old
Son was = s-12 years old
Then
f-12=6(s-12)
f-12=6s-72
f=6s-72+12
f=6s-60..............(2)
Compare (1) and (2)
3s=6s-60
3s-6s=-60
-3s=-60
-3s/-3=-60/-3
s=20
Put the value of s in (1)
f=3s
f=3(20)
f=60
Present age of of Father = f = 60 years old
Present age of Son = s = 20 years old
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