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checkley77 answered: 12560 problems
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Expressions-with-variables/158246: 5*3=3*5
1 solutions

Answer 116613 by checkley77(12569) on 2008-09-21 18:43:40 (Show Source):

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5*3=3*5
15=15

Mixture_Word_Problems/158226: Rubbing alcohol is typically diluted with water to 70% strength. If you need 3.5 oz of 45% rubbing alcohol, how many ounces of 70% rubbing alcohol and how much water should you combine?
1 solutions

Answer 116611 by checkley77(12569) on 2008-09-21 18:38:55 (Show Source):

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.7X=45(3.5)
.7X=1.575
X=1.575/.7
X=2.25 AMOUNT OF 70% ALCOHOL.
3.5-2.25=1.25 AMOUNT OF WATER ADDED.

Linear-systems/158230: three times the larger of two numbers is equal to four times the smaller. The sum of the numbers is 21 (12+9). Find the numbers.
1 solutions

Answer 116604 by checkley77(12569) on 2008-09-21 18:04:07 (Show Source):

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X+Y=21 OR X=21-Y
3Y=4X
3Y=4(21-Y)
3Y=84-4Y
3Y+4Y=84
7Y=84
Y=84/7
Y=12 THE LARGER NUMBER.
X+12=21
X=21-12
X=9 THE SMALLER NUMBER.
PROOF:
3*12=4*9
36=36

Linear_Equations_And_Systems_Word_Problems/158232: Sarsh is designing a rectangular garden in her back yard. The length of the garden is to be three feet less than twice its width. if the perimeter of the garden is sixty feet, what are the width and length of her garden
1 solutions

Answer 116602 by checkley77(12569) on 2008-09-21 18:00:18 (Show Source):

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LENGTH=2W-3
WIDTH=W
2(2W-3)+2W=60
4W-6+2W=60
6W=60+6
6W=66
W=66/6
W=11 FEET.
L=2*11-3
L=22-3
L=19 FEET
PROOF:
2*19+2*11=60
38+22=60
60=60

Inequalities/158236: This question is from textbook Intermediate Algebra for College Students
(Book asks first to setup an inequality that can be used to solve the problem, then solve it to find the desired value)
Long Distance: The telephone long-distance carrier Telecom-USA, which markets itself as 10-10-220, charges customers $0.99 for the first 20 minutes and then $0.07 for each minute (or any part thereof) beyond 20 minutes. If Patricia Lanz uses this carrier, how long can she talk for $5.00?
1 solutions

Answer 116600 by checkley77(12569) on 2008-09-21 17:57:00 (Show Source):

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.99+X*.07=5
.99+.07X=5
.07X=5-.99
.07X=4.01
X=4.01/.07
X=57.3
57+20= 77 MINUTES IS THE MAXIMUM MINUTES SHE CAN USE FOR $5.00.
PROOF
.99+.07*57<5
.99+3.99<5
4.98<5

Angles/158235: This question is from textbook Geometry
62) 1/2*b*6=15
64)3014*r2=314
1 solutions

Answer 116598 by checkley77(12569) on 2008-09-21 17:50:14 (Show Source):

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62) 1/2*b*6=15
6B/2=15
3B=15
B=15/3
B=5 ANSWER.
PROOF:
5*6/2=15
15=15
64)3014*r^2=314
R^2=314/3014
R^2=.1041804
R=SQRT.1041804
R=.3227698 ANSWER.
PROOF
3014*.3227698^2=314
3014*.1041804=314
314~314

Linear_Algebra/158113: A company place $1,000,000 in three different accounts. It placed part in short-term notes paying 4.5% peryear, twice as much in government bonds paying 5% per year, and the rest in utility bonds paying 4%. The income after one year is $45,500. How much did the company place in each account?
1 solutions

Answer 116596 by checkley77(12569) on 2008-09-21 17:43:55 (Show Source):

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.045X+.05*2X+.04(1,000,000-3X)=45,500
.045X+.10X+40,000-.12X=45,500
.025X=45,500-40,000
.025X=5,500
X-5,500/.025
X=220,000 INVESTED @ 4.5%
2*220,000=440,000 INVESTED @ 10%
1,000-220,000-440,000=340,000 INVESTED @4%.
PROOF:
.045*220,000+.05*440,000+340,000*.04=45,500
9,900+22,000+13,600=45,500
45,500=45,500

Linear_Algebra/158115: This question is from textbook Algebra 2
Ten apples cost a penny, and 25 pears cost two pennies. Suppose I buy 100 apples and pear for 9 1/2 pennies. How may of each shall I have?
1 solutions

Answer 116592 by checkley77(12569) on 2008-09-21 17:32:44 (Show Source):

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10A=1 OR A=.1
25P=2 OR P=.08
A+P=100 OR A=100-P
.1A+.08P=9.5
.1(100-P)+.08P=9.5
10-.1P+.08P=9.5
-.02P=9.5-10
-.02P=-.5
P=-.5/-.02
P=25 PEARS.
100-25=75 APPLES.
PROOF:
.1*75+.08*25=9.5
7.5+2=9.5
9.5=9.5

Money_Word_Problems/158129: . P dollars is invested at annual interest rate r for 1 year. If the interest is compounded semiannually, then the polynomial P (1+r/2)2 represents the value of the investment after 1 year. Rewrite this expression without parentheses. Evaluate the polynomial if P = $200 and r =10%.
1 solutions

Answer 116591 by checkley77(12569) on 2008-09-21 17:23:46 (Show Source):

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200(1+.10/2)^2
200*1.05^2
200*1.1025=$220.50

Linear-systems/158147: This question is from textbook
12. Slope undefined; containing the point (-3, 4)
Write the equation using the general form or the slope-intercept form, whichever you prefer. Graph each line.
1 solutions

Answer 116589 by checkley77(12569) on 2008-09-21 17:18:29 (Show Source):

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4=-3m+b
CAN'T GRAPH THE LINE WITHOUT A SLOPE (m) VALUE OR A Y INTERCEPT (b) VALUE.

Percentage-and-ratio-word-problems/158219: A wooden chess set is priced at $120. It was discounted 35%. What was the actual cost?
My work:
120=1.35x
120/1.35=x
88.8888888888888889=x
1 solutions

Answer 116587 by checkley77(12569) on 2008-09-21 17:13:14 (Show Source):

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X(1-.35)=120
.65X=120
X=120/.65
X=184.62 IS THE ORIGINAL PRICE.

Mixture_Word_Problems/158201: This question is from textbook Intermediate Algebra for College Students
Painting Sales: Joseph DeGuizman, an artist, sells both large paintings and small paintings. He sells his small paintings for $60 and his large paintings for $180. At the end of the week he determined that the total amount he made selling 12 paintings was $1200. Determine the number of small and the number of large paintings that he sold.
---I know the answers, more importantly, I cant understand how to setup the equation(s) to get the answers.
1 solutions

Answer 116584 by checkley77(12569) on 2008-09-21 17:05:04 (Show Source):

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S+L=12 OR S=12-L
60S+180L=1,200
SUBSTITUTING (12-L) FOR S IN THE SECOND EQUATION WE GET:
60(12-L)+180L=1,200
720-60L+180L=1,200
120L=1,200-720
120L=480
L=480/120
L=4 LARGE PAINTING SOLD.
S=4=12
S=12-4
S=8 SMALL PAINTINGS SOLD.
PROOF:
60*8+4*180=1,200
480+720=1,200
1,200=1,200

Percentage-and-ratio-word-problems/158203: This question is from textbook intermediate Algebra for College Students
Ocean Salinity: The salinity (salt content) of the Atlantic Ocean averages 37 parts per thousand. If 64 ounces of water is collected and placed in the sun, how many ounces of pure water would need to evaporate to raise the salinity to 45 parts per thousand? (Only pure water is evaporated; the salt is left behind.)
---I dont even know where to begin this one; I need to know how to setup the equation, what information is important, and the solution.
1 solutions

Answer 116582 by checkley77(12569) on 2008-09-21 16:59:58 (Show Source):

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.37*64=.45(64-X)
23.68=28.8-.45X
.45X=28.8-23.68
.45X=5.12
X=5.12/.45
X=11.38 OZ OF WATER IS EVAPORATED.

Radicals/158204: Simplify: (–7 sqrt11 - sqrt7)(sqrt7 – 10sqrt11)
1 solutions

Answer 116576 by checkley77(12569) on 2008-09-21 16:42:39 (Show Source):

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(–7 sqrt11 - sqrt7)(sqrt7 – 10sqrt11)
-7SQRT11-SQRT7
SQRT7-10SQRT11 MULTIPLY
--------------------------------------
-7SQRT77-7+70*11+10SQRT77
3SQRT77-7+770
3SQRT77-763

expressions/158207: (64)^-4/3
1 solutions

Answer 116574 by checkley77(12569) on 2008-09-21 16:35:58 (Show Source):

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(64)^-4/3
1/cubert64^4
1/cubert16,777,216
1/256 or .0039 answer.

Inequalities/158087: How do i write this inequality:
Your quiz grades are 19,17,20, and 15. What is the lowest grade you can receive on the next quiz and maintain at least an 18 average?
The inequality does not have to be solved. I think the answer is 71+ x /5 >=18.
Is this correct and how do i solve inequalities like this?
1 solutions

Answer 116486 by checkley77(12569) on 2008-09-20 19:39:32 (Show Source):

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71+ x /5 >=18.
x/5>=18-71
x/5>=-53
x>=-53*5
x>=-265 answer.
proof:
71-265/5>=18
71-53>=18
18>=18

Graphs/158088: Find equation: (2,5) (-6,-5)
I know that you use m=y2-y1/ x2-x1
which is 5-(-5)= 10 5/4 then: y=5/4x +b
2-(-6)= 8 5= 5/4 +b
5= 5/4(2)+b
5= 5/2 +b
5-5/2=b here's where it gets confusing
the answer is.... the book states y= 5/4x+5/2
1 solutions

Answer 116484 by checkley77(12569) on 2008-09-20 19:35:52 (Show Source):

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(2,5)(-6,-5)
m=(-5-5)/-6-2)
m=-10/-8=5/4 is the slope.
Y=mX+b
5=5/4*2+b
5=10/4+b
b=5-10/4
b=5-2.5
b=2.5 thge y intercept.
y=5x/4-2.5 answer. Same answer in the book.

Rational-functions/158007: find the product
(9x-8)^2
a. 81x^2+64
b. 9x^2+64
c. 9x^2-144x+64
d. 81x^2-144x+64
1 solutions

Answer 116483 by checkley77(12569) on 2008-09-20 19:27:52 (Show Source):

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(9x-8)^2
9X-8
9X-8
----------------------
81X^2-72X-72X+64
81X^2-144X+64 ANSWER D)
##########################
a. 81x^2+64
b. 9x^2+64
c. 9x^2-144x+64
d. 81x^2-144x+64

Exponential-and-logarithmic-functions/158008: find the product
(x-4y)(5x-9y)
a. 5x^2-29xy-29y^2
b. x^2-29xy+36y^2
c. x^2-29xy-29y^2
d. 5x^2-29xy+36y^2
1 solutions

Answer 116482 by checkley77(12569) on 2008-09-20 19:25:05 (Show Source):

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(x-4y)(5x-9y)
X-4Y
5X-9Y
--------------------
5X^2-20XY-9XY+36Y^2
5X^2-29XY+36Y^2 ANSWER D)

Rate-of-work-word-problems/158018: 34% of the voters in one county voted Democratic in the last election. If 6,834 people voted Democratic, how many voters are there in the county.
1 solutions

Answer 116481 by checkley77(12569) on 2008-09-20 19:21:35 (Show Source):

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.34X=6,834
X=6,834/.34
X=20,100 TOTAL VOTERS.

Miscellaneous_Word_Problems/158050: Jason needs to measure exactly 4 liters of water. He has only two containers-one that holds exactaly 8 liters and one that holds exactaly 10 liters. How does he get exactly 4 liters?
Thank you ahead of time for answering this.
1 solutions

Answer 116480 by checkley77(12569) on 2008-09-20 19:16:53 (Show Source):

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FILL THE 10 LITER CONTAINER.
POUR 8 LITERS INTO THE 8 KLITER CONTAINER.
YOU HAVE 2 LITERS LEFT IN THE 10 LITER CONTAINER.
TRANSFER THE 2 LITERS INTO THE 8 LITER CONTAINER.
FILL THE 10 LITER CONTAINER.
EMPTY 6 LITERS INTO THE 8 LITER CONTAINER.
YOU NOW HAVE 4 LITERS LEFT IN THE 10 LITER CONTAINER

Miscellaneous_Word_Problems/158051: Jason needs to measure exactly 4 liters of water. He has only two containers-one that holds exactaly 8 liters and one that holds exactaly 10 liters. How does he get exactly 4 liters?
Thank you ahead of time for answering this.
1 solutions

Answer 116479 by checkley77(12569) on 2008-09-20 19:15:31 (Show Source):

Miscellaneous_Word_Problems/158053: Jason needs to measure exactly 4 liters of water. He has only two containers-one that holds exactaly 8 liters and one that holds exactaly 10 liters. How does he get exactly 4 liters?
Thank you ahead of time for answering this.
1 solutions

Answer 116478 by checkley77(12569) on 2008-09-20 19:14:22 (Show Source):

Rational-functions/158065: Simplify (1/x + 1/y)^2
1 solutions

Answer 116477 by checkley77(12569) on 2008-09-20 19:06:56 (Show Source):

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(1/x + 1/y)^2
1/x+1/y
1/x+1/y multiply
--------------
1/x^2+1/xy+1/xy+1/y^2
1/x^2+2/xy+1/y^2

Polynomials-and-rational-expressions/158066: Simplify (12x^2y^8z^7/ 4x^9y^8z^4)^3
I got originally a whole different answer than the ones to choose from......

1 solutions

Answer 116476 by checkley77(12569) on 2008-09-20 19:05:02 (Show Source):

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(12x^6(2)y^8 z^7/4x^9y^8z^4)^3 I assume you wanted top drop the (2) in front of the y^8!!!!!
12/4=3
x^7/x^9=1/x^2
y^8/y^8=1
z^7/z^4
[(3*1*1*z^4)/x^2]^3
[(3z^4)/x^2]^3
27z^12/x^6 answer.

Radicals/158068: simplify sqrt sign w^11/x^5
I got w^5/x^3 sqrt w/x I don't think this is right
1 solutions

Answer 116475 by checkley77(12569) on 2008-09-20 18:57:55 (Show Source):

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sqrt sign w^11/x^5
sqrtw^11/x^5=w^5/x^2sqrtw/x

Travel_Word_Problems/157914: Two cars leave from the same place at the same time and drive in opposite directions. One car travels an average of 6 mph faster than the other. After 2 hours, the cars are 310 miles apart. Find the speed of each car.
1 solutions

Answer 116412 by checkley77(12569) on 2008-09-19 23:01:33 (Show Source):

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2X+2(X+6)=310
2X+2X+12=310
4X=310-12
4X=298
X=298/4
X=74.5 mph for the slower car.
74.5+6=80.5 mph for the faster car.
proof:
2*74.5+2*80.5=310
149+161=310
310=310

real-numbers/157922: I need help with this problem: ((-2f))) f= 3/4
1 solutions

Answer 116410 by checkley77(12569) on 2008-09-19 22:56:35 (Show Source):

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((-2f))) f= 3/4
-2*3/4=-6/4=-1.5

Travel_Word_Problems/157945: Mattie drove 150 miles in the same amount of time that it took a turboprpellar plane to travel 600 miles. The spped of the plane was 150 mph faster than the speed of the car mattie drove. Find the speed of the plane.
This came from a take home exam from my Math Structures 1 teacher
1 solutions

Answer 116408 by checkley77(12569) on 2008-09-19 22:52:18 (Show Source):

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150/X=600/(X+150)
150(X+150)=600X
150X+22,500=600X
150X-600X=-22,500
-450X=-22,500
X=-22,500/-450
X=50 MPH IS MATTIE'S SPEED.
50=150=200 MPH IS THE PLANE'S SPEED.

Mixture_Word_Problems/157946: A pharmacist needs 70 liters of a 50% alcohol solution. She has availible a 30 % solution and an 80% solution. How many liters of each solution should she mix to obtain 70 liters of a 50% alcohol solution ?

Also from a take home exam
1 solutions

Answer 116403 by checkley77(12569) on 2008-09-19 22:44:53 (Show Source):

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70*.5=.30X+.80(70-X)
35=.30X+56-.80X
35-56=-.50X
-21-.5X
X=-21/-.5
X=42 LITERS OF THE 30% ALCOHOL IS NEEDED.
70-42=28 LITERS OF THE 50% ALCOHOL IS ALSO NEEDED.
PROOF:
70*.5=.30*42+.80*28
35=12.6+22.4
35=35

Money_Word_Problems/157947: An office supply store in San Diego sells 7 writing tablets and 4 pens for $ 6.40. Also, 2 tablets and 19 pens cost # 5.40. Find the price of each.

From a take home test
1 solutions

Answer 116401 by checkley77(12569) on 2008-09-19 22:34:04 (Show Source):

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7T+4P=6.40
2T+19P=5.40
MULTIPLY THE FIRST EQUATION BY 2 & MULTIPLY THE SECOND EQUATION BY -7 & THEN ADD THEM.
14T+8P=12.80
-14T-133P=-37.80
----------------------
-125P=-25.00
P=-25.00/-125
P=$.20 IS THE PRICE FOR EACH PEN.
7T+4*.20=6.40
7T+.80=6.40
7T=6.40-.80
7T=5.60
T=5.60/7
T=$.80 FOR EACH TABLET.
PROOF:
2*.80 +19*.20=5.40
1.60+3.80=5.40
5.40=5.40

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