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checkley77 answered: 12560 problems
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At 11 am a second plane leaves chicago heading west on the same flight path and treveling 50mph faster than the first plane. the second plane overtakes the first plane in 5 hours. What is the rate of the first plane? 1 solutions
Answer 119103 by checkley77(12569) on 2008-10-12 16:13:07 (Show Source):
You can put this solution on YOUR website!7R=5(R+50)
7R=5R+250
7R-5R=250
2R=250
R=250/2
R=125 MPH FOR THE FIRST PLANE.
125=50=175 MPH FOR THE SECOND PLANE.
PROOF:
7&125=5(125+50)
875=5*175
875=875 IS THE DISTANCE BOTH PLANES COVERED.
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Mixture_Word_Problems/161644: A butcher has two grades of ground meat. A low grade meat costs $1.50 per pound and a higher grade of meat which costs $4.00 per pound. How many pounds of each grade of meat should he mix together to get 25 pounds of meat costing $3.00 per pound? 1 solutions
Answer 119099 by checkley77(12569) on 2008-10-12 15:57:00 (Show Source):
You can put this solution on YOUR website!4X+1.5(25-X)=3*25
4X+37.5-1.5X=75
2.5X=75-37.5
2.5X=37.5
X=37.5/2.5
X=15 POUNDS OF $4 MEAT IS USED.
25-15=10 POUNDS OF $1.50 MEAT IS USED.
PROOF:
4*15+1.5*10=3*75
60+15=75
75=75
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Polynomials-and-rational-expressions/161382: CAN SOMEONE PLEASE HELP ME WITH THIS PROBLEM:
The equation V = -2000t + 20,000 describes the value in dollars of a certain model of car after it is t years old. If a car is worth $12,000, substitute 12,000 into the equation to find the age of the car. 1 solutions
Answer 119075 by checkley77(12569) on 2008-10-12 10:31:58 (Show Source):
You can put this solution on YOUR website!V = -2000t + 20,000
12,000=-2,000t+20,000
2,000t=20,000-12,000
2,000t=8,000
t=8,000/2,000
t=4 years.
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Travel_Word_Problems/161570: If 500 is invested at 6% interest, how much additional money must be invested at 9% so that the total return for both investments averages 8% ? 1 solutions
Answer 119072 by checkley77(12569) on 2008-10-12 10:26:23 (Show Source):
You can put this solution on YOUR website!500*.06+.09x=.08(500+x)
30+.09x=40+.08x
.09x-.08x=40-30
.01x=10
x=10/.01
x=1,000 must be invested @ 9%.
Proof:
500*.06+.09*1,000=.08(500+1,000)
30+90=.08*1,500
120=120
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Problems-with-consecutive-odd-even-integers/161590: Find three consecutive odd integers such that the product of the first and second integer is 7 less then 10 times the third integer. 1 solutions
Answer 119070 by checkley77(12569) on 2008-10-12 10:21:58 (Show Source):
You can put this solution on YOUR website!Let x, x+2 & x+4 be the 3 integers.
x(x+2)=10(x+4)-7
x^2+2x=10x+40-7
x^2+2x-10x-40+7=0
x^2-8x-33=0
(x-11)(x+3)=0
x-11=0
x=11 answer
x+3=0
x=-3 answer.
The 3 integers are:11,13,15 or:
The 3 integers are: -3,-1,& +1.
Proofs:
11*13=10*15-7
143=150-7
143=143
-3*-1=10*1-7
3=10-7
3=3
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Miscellaneous_Word_Problems/161552: Please help me with this problem:
Arrange the digits form 1 through 9 to from a single fraction which equals 1/3.
Thank you! 1 solutions
Answer 119068 by checkley77(12569) on 2008-10-12 10:15:41 (Show Source):
You can put this solution on YOUR website!
THERE ARE MANY DIFFERENT SOLUTIONS FOR THESE TYPE OF PROBLEMS WHICH REQUIRES A SPECIAL SKILL WORKING WITH NUMBERS AND COMBINATIONS OF NUMBERS.
IT IS NOT SOMETHING THAT CAN BE EASILY TAUGHT.
IF YOU'RE REALLY INTERESTED START COLLECTING THESE TYPE OF PROBLEMS AND WORK OUT YOUR OWN SOLUTIONS.
THIS IS ONE OF THE EASYEST I'VE ENCOUNTERED.
(9-8)-(7-6)-(5-4)+(2*1)/3=1/3
(1-1-1+2)/3
(3-2)/3
1/3
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Graphs/161588: I am having a very hard time understanding this, can you please help?
Determine whether the graphs of the pair of lines are parallel.
x+13=y
y-x=-9
For x+13=y, I came up with the answer x-y+13=0 but I am not sure if it is right and why or why not.
For y-x=-9, I came up with the answer of -8; again I am not sure.
What is the slope of the line x+13=y?
What is the slope of the line y-x=-9?
Are the graphs of the equations parallel? 1 solutions
Answer 119066 by checkley77(12569) on 2008-10-12 10:04:24 (Show Source):
You can put this solution on YOUR website!x+13=y
y-x=-9
The first thing you must do is find the slope (m) by placing these formula in the standard line form:
Y=mX+b where x & y are a set of graph points, m=slope (y2-y1)/(x2-x1) & b=the y intercept.
y=x+13 This line has a slope (m)=1. (red line)
y=x-9 This line also has a slope (m)=1. (green line)
Therefore they are parallel lines.
Proof:
 (graph 300x200 pixels, x from -16 to 15, y from -10 to 15, of TWO functions x +13 and x -9).
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Linear_Equations_And_Systems_Word_Problems/161534: togo flew his ultralight plane to a landing field 30 mi away. With the wind, the flight took 3/5h. Returning against the wind, the flight took 5/6h. Find the rate of the plane in still air and the rate of the wind. 1 solutions
Answer 119006 by checkley77(12569) on 2008-10-11 18:42:33 (Show Source):
You can put this solution on YOUR website!D=RT
30/.6=r
r=50 mph with the wind.
30/(5/6)=r
5r/6=30
5r=30*6
5r=180
r=180/5
r=36 mph against the wind.
(50-36)/2=14/2=7 is the wind speed.
50-7=43 speed of the plane.
36+7=43 ditto.
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Linear_Equations_And_Systems_Word_Problems/161535: togo flew his ultralight plane to a landing field 30 mi away. With the wind, the flight took 3/5h. Returning against the wind, the flight took 5/6h. Find the rate of the plane in still air and the rate of the wind. 1 solutions
Answer 119004 by checkley77(12569) on 2008-10-11 18:36:58 (Show Source):
You can put this solution on YOUR website!D=RT
30/.6=r
r=50 mph with the wind.
30/(5/6)=r
5r/6=30
5r=30*6
5r=180
r=180/5
r=36 mph against the wind.
(50-36)/2=14/2=7 is the wind speed.
50-7=43 speed of the plane.
36+7=43 ditto.
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Mixture_Word_Problems/161531: A seed company mixes two types of seed for bird feeding. One costs $1.10 per kg and the other costs $2.25 per kg. How much of each type of seed is needed to produce 6kg at a cost of $8.90? 1 solutions
Answer 119003 by checkley77(12569) on 2008-10-11 18:30:26 (Show Source):
You can put this solution on YOUR website!2.25x+1.10(6-x)=8.90
2.25x+6.60-1.10x=8.90
1.15x=8.90-6.60
1.15x=2.30
x=2.30/1.15
x=2 kg of the $2.25 seed is used.
6-2=4 kg of the $1.10 seed is used.
Proof:
2.25*2+1.10*4=8.9
4.50+4.40=8.90
8.90=8.90
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Mixture_Word_Problems/161532: A farmer wants to mix milk containing 6% butterfat with 2 quarts of cream that is 15% butterfat to obtain a mixture that is 12% butterfat. How much milk containing 6% butterfat must he use? 1 solutions
Answer 119000 by checkley77(12569) on 2008-10-11 18:16:15 (Show Source):
You can put this solution on YOUR website!.06x+.15*2=.12(x+2)
.06x+.3=.12x+.24
.06x-.12x=.24-.3
-.06x=-.06
x=-.06/-.06
x=1 quart of 6% butterfat is used.
Proof:
.06*1+.15*2=.12(1+2)
.06+.3=.12*3
.36=.36
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Mixture_Word_Problems/161533: A store owner has 12 pounds of pasta worth 70 cents a pound. She wants to mix it with pasta worth 45 cents a pound so that the total mixture can be sold for 55 cents a pound ( without any gain or loss). How much of the 45 cent pasta must she use? 1 solutions
Answer 118999 by checkley77(12569) on 2008-10-11 18:10:37 (Show Source):
You can put this solution on YOUR website!.70*12+.45x=.55(12+x)
8.4+.45x=6.6+.55x
.45x-.55x=6.6-8.4
.1x=1.8
x=1.8/.1
x=18 pounds of the $.45 pasta is needed.
Proof:
.70*12+.45*18=.55(12+18)
8.4+8.1=.55*30
16.5=16.5
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Mixture_Word_Problems/161530: A candy mixture is created with 2 types of candy, one costing $4 per pound and the other $3.50 per pound. How much of each type is needed for a 5 pound box that costs $18?
1 solutions
Answer 118998 by checkley77(12569) on 2008-10-11 18:05:29 (Show Source):
You can put this solution on YOUR website!4x+3.50(5-x)=18
4x+17.5-3.5x=18
4x-3.5x=18-17.5
.5x=.5
x=.5/.5
x=1 pound of the $4.00 candy.
5-1=4 pounds of the $3.50 candy.
Proof:
4*1+3.5*4=18
4+14=18
18=18
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Geometry_proofs/161393: I have absolutly NO idea how to do proofs. We just started them today so they are basic 2 section proofs. Are there any basics I should learn before I attempt these? 1 solutions
Answer 118985 by checkley77(12569) on 2008-10-11 16:38:23 (Show Source):
You can put this solution on YOUR website!X^2+8X+16=0
(X+4)(X+4)=0
X+4=0
X=-4 ANSWER.
PROOF:
-4^2+8*-4+16=0
16-32+16=0
32-32=0
0=0
-------------------------------------------------
X^2-5X+6=0
(X-2)(X-3)=0
X-2=0
X=2 ANSWER.
X-3=0
X=3 ANSWER.
PROOFS:
2^2-5*2+6=0
4-10+6=0
10-10=0
0=0
3^2-5*3+6=0
9-15+6=0
15-15=0
0=0
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Radicals/161394: i am asked to divide
x2 – 3x + 2/8x – 8 /x2 – 4/5x + 10
1 solutions
Answer 118984 by checkley77(12569) on 2008-10-11 16:32:42 (Show Source):
You can put this solution on YOUR website!x2 – 3x + 2/8x – 8 /x2 – 4/5x + 10
DO YOU MEAN:
(X^2-3X+2X/8-8)/(X^2-4X/5+10)
OR:
[(X^2-3X)+2/(8X-8)]/[(X^2-4)/(5X-10)]
OR:
[(X^2-3X)+2/(8X-8)]/[(X^2)-(4/(5X-10))]
PLEASE CLARIFY BECAUSE THESE ARE VERY DIFFERENT PROBLEMS.
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Probability-and-statistics/161443: In a bumper test, three types of autos were deliberately crashed into a barrier at 5 mph, and the resulting damage (in dollars) was estimated. Five test vehicles of each type were crashed, with the results shown below.
Crash Damage ($)
Goliath Varmint Weasel
1,600 1,290 1,090
760 1,400 2,100
880 1,390 1,830
1,950 1,850 1,250
1,220 950 1,920
Research question: Are the mean crash damages the same for these three vehicles?
show work
1 solutions
Answer 118981 by checkley77(12569) on 2008-10-11 16:16:49 (Show Source):
You can put this solution on YOUR website!Goliath Varmint Weasel
1,600 1,290 1,090
760 1,400 2,100
880 1,390 1,830
1,950 1,850 1,250
1,220 950 1,920
---------- ---------------- ----------------
6,410/5=1,282 6,880/5=1,375 8,190/5=1,638
AS YOU CAN SEE THE MEANS (AVERAGES) ARE NOT THE SAME.
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Numbers_Word_Problems/161491: Tamika paid 165.00 to her plumber for a service call. If her plumber charges 45.00 plus 40.00 per hours for a sevice call, then for how many hours did the plumber work? 1 solutions
Answer 118979 by checkley77(12569) on 2008-10-11 16:09:42 (Show Source):
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Linear_Equations_And_Systems_Word_Problems/161497: Toga flew her ultralight plane to a landing field 24 mi away. with the wind, the flight took 2/5 h. Returning against the wind, the flight took 3/4 h. Find the rate of the plane in still air and the rate of the wind. 1 solutions
Answer 118977 by checkley77(12569) on 2008-10-11 16:05:01 (Show Source):
You can put this solution on YOUR website!D=RT
24=R*.4
.4R=24
R=24/.4
R=60 MPH WITH THE WIND
24=R*.75
R=24/.75
R=32 MPH AGAINST THE WIND.
(60-32)/2=28/2=14 MPH IS THE WIND SPEED.
60-14=46 THE ULTRALIGHT SPEED.
32+14=46 DITTO.
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Polynomials-and-rational-expressions/161515: This question is from textbook finite mathematics
Can someone please help me with this problem:
A ball is thrown downward from a window in a tall building. Its position at time t in seconds is s = 16t^2 + 32t, where s is in feet. How long (to the nearest tenth) will it take the ball to fall 175 feet? 1 solutions
Answer 118975 by checkley77(12569) on 2008-10-11 15:54:40 (Show Source):
You can put this solution on YOUR website!s = 16t^2 + 32t
175=16t^2+32t
16t^2+32t-175=0
Using the quadratic equation:  We get:
t=(-32+-sqrt32^2-4*16*-175])/2*16
t=(-32+-sqrt[1,024+11,200])/32
t=(-32+-sqrt12,224)/32
t=(-32+-110.562)/32
t=(-32+110.562)/32
t=78.562/32
t=2.455 seconds
Proof:
175=16*2.455^2+32*2.455
175=16*6.027+78.56
175=96.432+78.56
175~174.992
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Quadratic_Equations/161498: Can you help me please,
Find all values of u satisfying the equation
7/u-1 =-6 + 2/u+2
.
(If there is more than one solution, separate them with commas
1 solutions
Answer 118974 by checkley77(12569) on 2008-10-11 15:41:32 (Show Source):
You can put this solution on YOUR website!(7/u)-1 =-6 + (2/u)+2
7/u-2/u=-6+2+1
(7-2)/u=-3
5/u=-3
-3u=5
u=5/-3
u=-5/3 answer.
OR:
7/(u-1)=-6+2/(u+2)
7/(u-1)-2/(u+2)=-6
[7(u+2)-2(u-1)]/(u-1)(u+2)=-6
(7u+14-2u+2)/(u^2+u-2)=-6
(5u+16)/(u^2+u+2)=-6
-6(u^2+u-2)=5u+16
-6u^2-6u+12=5u+16
-6u^2-6u-5u+12-16=0
-6u^2-11u-4=0
6u^2+11u+4=0
(3u+4)(2u+1)=0
3u+4=0
3u=-4
u=-4/3 answer.
2u+1=0
2u=-1
u=-1/2 answer.
(-4/3,-1/2)
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Travel_Word_Problems/161486: 2. The equation D=1.2 square root of h. gives the distance, D, in miles that a person can see to the horizon from a height, h, in feet.
a. Solve this equation for h.
b. Long’s Peak in the Rocky Mountain National Park, is 14,255 feet in elevation. How far can you see to the horizon from the top of Long’s Peak? Can you see Cheyenne, Wyoming (about 89 miles away)? Explain your answer.
1 solutions
Answer 118946 by checkley77(12569) on 2008-10-11 10:23:53 (Show Source):
You can put this solution on YOUR website!D=1.2SQRTH
SQRTH=D/1.2 SQUAERE BOTH SIDES.
H=(D/1.2)^2
H=D^2/1.44 ANSWER.
14,255=D^2/1.44
D^2=14,525*1.44
D^2=20,916
D=144.62 MILES CAN BE SEEN.
YES. CHEYANNE CAN BE SEEN BECAUSE 89 MILES IS LESS THAN 144.62 MILES.
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