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Linear-equations/68218: This question is from textbook
x/5-x/4=1
1 solutions

Answer 48516 by checkley71(8403) About Me  on 2007-01-27 13:43:51 (Show Source):
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x/5-x/4=1 NOW FIND THE COMMON DENOMINATOR (4*5=20)
(4x-5x)/20=1
4x-5x=20
-x=20
x=-20 answer
proof
-20/5-(-20)/4=1
-4+5=1
1=1


Equations/68043: 5-x=7+2x-4
what is x
1 solutions

Answer 48490 by checkley71(8403) About Me  on 2007-01-27 07:00:38 (Show Source):
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5-X=7+2X-4
-X-2X=7-4-5
-3X=-2
X=-2/-3
X=2/3


Linear_Equations_And_Systems_Word_Problems/68089: Find two positive numbers whose difference is 9 and whose product is a mimimum.
x-y=9 xy=?
1 solutions

Answer 48489 by checkley71(8403) About Me  on 2007-01-27 06:56:02 (Show Source):
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X-Y=9
XY=?
POSSIBLE NUMBERS ARE 9,0 10,1 11,2 12,3 13,4 ETC.
9*0=9
10*1=10
11*2=22
12*3=36
13*4=52
THEREFORE THE ANSWER IS X=9 & Y=0


Linear-systems/68141: This question is from textbook Prentice Hall Mathematics Algebra 1
how do you graph a solution that says:
y=-3/2-3
1 solutions

Answer 48487 by checkley71(8403) About Me  on 2007-01-27 06:50:08 (Show Source):
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Y=-3/2-3
Y=-1.5-3
Y=-4.5
+graph%28+300%2C+200%2C+-6%2C+5%2C+-5%2C+5%2C+Y+=+-4.5%29+ (graph 300x200 pixels, x from -6 to 5, y from -5 to 5, Y = -4.5).


Graphs/68148: This question is from textbook Algebra for College Students
If one-half of the complement of an angle plus three-fourths of the supplement of the angel equals 110 degrees, find the measure of the angel.
1 solutions

Answer 48486 by checkley71(8403) About Me  on 2007-01-27 06:46:27 (Show Source):
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.5(90-x)+.75(180-x)=110
45-.5x+135-.75x=110
-1.25x=110-135-45
-1.25x=-70
x=-70/-1.25
x=56 degrees is he angle.


Complex_Numbers/68181: This question is from textbook College Algebra
radical notation -10
1 solutions

Answer 48483 by checkley71(8403) About Me  on 2007-01-27 06:36:45 (Show Source):
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sqrt-10=3.1622776i


Evaluation_Word_Problems/68114: Allen bought 20 stamps at the post office in 37¢ and 20¢ denominations. If the total cost of the stamps was $7.06, how many 37¢ stamps did Allen buy?
1 solutions

Answer 48473 by checkley71(8403) About Me  on 2007-01-26 22:24:15 (Show Source):
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X+Y=20 X BEING THE NUMBER OF $.37 & Y BEING THE $.20 STAMPS.
X=20-Y
.37X+.20Y=7.06
.37(20-Y)+.20Y=7.06
7.40-.37Y+.20Y=7.06
-.17Y=7.06-7.40
-.17Y=-.34
Y=-34/-17
Y=2 NUMBER OF $.20 STAMPS.
X+2=20
X=20-2
X=18 NUMBER OF $.37 STAMPS.
PROOF
.37*18+.20*2=7.06
6.66+.40=7.06
7.06=7.06



percentage/68115: Convert 9/16 to a percent.
1 solutions

Answer 48472 by checkley71(8403) About Me  on 2007-01-26 22:16:10 (Show Source):
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9/16=.5625 THIS IS OBTAINED BY DIVIDING 9 BY 16 USING THE LONG DIVISION MSTHOD OR A CALCULATOR.


Linear-equations/68144: What is the slope of the following line?
x = 9.124
1 solutions

Answer 48471 by checkley71(8403) About Me  on 2007-01-26 22:13:21 (Show Source):
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THIS SLOPE IS UNDEFINED & IS A VERTICLE LINE THROUGH THE POINT (9.124,0)


Equations/68150: This question is from textbook Algebra for College Students
V=1/3Bh (solve for B)
1 solutions

Answer 48470 by checkley71(8403) About Me  on 2007-01-26 22:11:40 (Show Source):
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V=1/3BH
3V=BH
B=3V/H


Equations/68152: This question is from textbook Algebra for College Studnets
5x-6y=12 (Solve for x)
1 solutions

Answer 48469 by checkley71(8403) About Me  on 2007-01-26 22:09:38 (Show Source):
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5X-6Y=12
5X=6Y+12
X=6Y/5+12/5


Linear-equations/68160: This question is from textbook A Graphical Approach to Algebra and Trigonometry
Find the equation of the line satisfying the given conditions, giving it in slope-intercept form if possible. Through (-2,0), perpendicular to 8x-3y=7.
1 solutions

Answer 48467 by checkley71(8403) About Me  on 2007-01-26 22:07:45 (Show Source):
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8X-3Y=7
-3Y=-8X+7
Y=8X/3-7/3 THUS THIS LINE HAS A SLOPE OF -8/3.
THUS A PERPENDICULAR LINE HAS A SLOPE OF 3/8 & PASSING THROUGH (-2,0) IS
0=3/8*-2+b
0=-6/8+b
b=6/8
b=3/4
THUS THE EQUATION OF THIS LINE IS
Y=3/8X+3/4


Triangles/68177: Triangle ABC is a right triangle. If side AC=5 and side BC=6, What is the measure of side AB?
1 solutions

Answer 48466 by checkley71(8403) About Me  on 2007-01-26 22:02:16 (Show Source):
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IF AB IS THE HYPOTENUSE THEN
AB^2=5^2+6^2
AB^2=25+36
AB^2=61
AB=SQRT61
AB=7.81
---------------------
IF BC IS THE HYPOTENUSE THEN
6^2=5^2+AB^2
36=25+AB^2
36-25=AB^2
9=AB^2
AB=SQRT9
AB=3
------------------------------


Linear-equations/68090: I am helping my 13 year old with his homework. Please tell me what slope is and how it is measured in general. We are using an Egyptian pyramid as a model.
Thank you !
1 solutions

Answer 48380 by checkley71(8403) About Me  on 2007-01-25 21:44:57 (Show Source):
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WHAT YOU NEED TO DO IF YOU ARE USING A PYRAMID THEN PLOT TWO OF THE POINTS (BASE & TOP POINT) ON A GRAPH THUS (0,0) (5,4)
THE SLOPE IS CALCULATED USING
(Y2-Y1)/(X2-X1)
(4-0)/(5/0)
4/5 IS THE SLOPE OFF A LINE BETWEEN THESE TWO POINTS OR THE SLOPE OF THE SIDES OF THE PYRAMID.


Money_Word_Problems/68087: Jack invested $8000, part at 10% and part at 15%. If the total interest at the end of the year is $900, how much did he invest at 10%?
a)$7000
b)$5000
c)$6000
d)$4000
1 solutions

Answer 48378 by checkley71(8403) About Me  on 2007-01-25 21:40:09 (Show Source):
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.1x+.15(8000-x)=900
.1x+1200-.15x=900
-.05x=900-1200
-.05x=-300
x=-300/-.05
x=6000 invested @ 10% answer c)


Linear-systems/68085: Find the slope of any line perpendicular to the line through points(3, 2) and (5, 6).
a)4
b)-4
c)1/4
d)-1/4
Any help would be great, thanks.
1 solutions

Answer 48376 by checkley71(8403) About Me  on 2007-01-25 21:33:49 (Show Source):
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the slope of the line between these 2 points is
(6-2)/(5-3)
4/2=2 for the slope.
therefore a line perpendicular has to have a slope that is the negatiuve reciprical of this slope which would be -1/2
don't see (-1/2) as one of the answers.
are you sure you have the correct points?


Linear-systems/68082: Determine which two equations represent parallel lines.
a)y = 3x - 5
b)y = -3x + 5
c)y = 3x + 3
d)y = -1/3x -5
Any help would be greatful.
1 solutions

Answer 48375 by checkley71(8403) About Me  on 2007-01-25 21:26:56 (Show Source):
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a) & c)are parallel because they have the same (m) value (3) which indicates parallel lines.


Quadratic_Equations/68077: Here is another problem that I have posted within the past 2 days that I am having trouble with setting up. If someone could give me a little hint, I would appreciate it. Thanks.
A garden area is 30 ft long and 20 ft wide. A path of uniform width is set around the edge. If the remaining garden area is 400 ft2, what is the width of the path? Give your answer in decimal form, rounded to the nearest thousandth.
1 solutions

Answer 48374 by checkley71(8403) About Me  on 2007-01-25 21:24:44 (Show Source):
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(30-2X)(20-2X)=400
600-40X-60X+4X^2=400
4X^2-100X+600-400=0
4X^2-100X+200=0
X^2-25X+50=0
using the quadratic equation we get
x=(-b+-sqrt[b^2-4ac])/2a
x=(25+-sqrt[-25^2-4*1*50])/2*1
x=(25+-sqrt625-200])/2
x=(25+-sqrt425)/2
x=(25+-20.6155)/2
x=(25+20.6155)/2
x=45.6155
x=(25-20.6155)/2
x=4.3845/2
x=2.192 answer for the width of the path.
-------------------------------------------------------------
IF YOU DRAW A DIAGRAM OF THE PROBLEM (WHICH I ALWAYS RECOMMEND) YOU'LL SEE THAT THE RECTANGLE INSIDE ANOTHER RECTANGLE WITH THE OUTSIDE DIMENTIONS OF 20 & 30 FT
YOU'LL SEE THAT THE INNER RECTANGLE LENGTH IS 30 & 20 -2 TIMES THE BORDER (X) THUS THE TERMS 30-2X & 20-2X TO DESCRIBE THE INNER RECTANCLE.


Geometry_Word_Problems/68072: This question is from textbook Geometry
A zip lane is a taut rope or cable that you can ride down on a pulley the zip line at the right goes from a 9 feet tower to a 6 feet tall tower. The towers are 20 feet apart. What is the slope of the zip lane?
1 solutions

Answer 48371 by checkley71(8403) About Me  on 2007-01-25 21:08:12 (Show Source):
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GRAPHING THIS PROBLEM WE HAVE TWO POINTS (0,9) & (20,6)
THUS THE SLOPE IS
(6-9)/20-0)
-3/20 IS THE SLOPE.


Quadratic_Equations/68069: I have asked this question within the past two days without a response. I am having a tough time figuring out how to set this problem up. Once I know how to set it up and why, I can probably solve the equation. I hope someone out there can help me with this one, please.
Find two consecutive positive integers such that the sum of their squares is 85. [You must use algebra to solve this, setting up an equation with a variable, and using algebra to solve for the variable.]
1 solutions

Answer 48370 by checkley71(8403) About Me  on 2007-01-25 21:02:40 (Show Source):
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let x^2 be the first number & (x+1)^2 the next number
x^2+(x+1)^2=85
x^2+x^2+2x+1=85
2x^2+2x+1-85
2x^2+2x-84=0
x^2+x^2-42=0
(x+7)(x-6)=0
x-6=0
x=6 answer for the first number
6+1=7 for the next number.
proof
6^2+7^2=84
36+49=84
84=84



Systems-of-equations/67935: y=3x-1
and
y=negative2x
The x and y are the same in both problems.
1 solutions

Answer 48308 by checkley71(8403) About Me  on 2007-01-24 20:37:44 (Show Source):
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Y=3X-1 NOW SUBSTITUTE (3X-1) FOR Y IN THE OTHER EQUATION THUS
3X-1=-2X
3X+2X=1
5X=1
X=1/5 ANSWER
Y=3*1/5-1
Y=3/5-1
Y=-2/5 ANSWER


absolute-value/67919: This question is from textbook Algebra:Structure and Method
If I increase my usual driving speed by 10 km/h, I can drive the 255 km to Nashviille in 24 minutes less than usual. How fast do I usually drive?
1 solutions

Answer 48307 by checkley71(8403) About Me  on 2007-01-24 20:33:28 (Show Source):
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255/x=255/(x+10)+.4
255/x=(255+.4x+4)/(x+10)
255/x=(259+.4x)/(x=10)
255(x+100=x(259+.4x)/(x+10)
255x+2550=259x+.4x^2
.4x^2+4x-2550=0
(.4x-30)(x+85)=0
.4x-30=0
.4x=30
x=30/.4
x=75 km/h is the normal speed
75+10=85 km/h is the faster trip speed
proof
255/75=255/85+.4
3.4+3+.4
3.4=3.4


Graphs/67928: Can you tell me how to solve
X^2+9X+20=0 by factoring
1 solutions

Answer 48305 by checkley71(8403) About Me  on 2007-01-24 20:23:44 (Show Source):
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x^2+9x+20=0
(x+4)(x+5)=0
x+4=0
x=-4 answer
x+5=0
x=-5 answer


Money_Word_Problems/67821: At the movies tickets for adults cost $5.50 and tickets for children cost $3.50. How many of each kind of ticket was purchased if 21 tickets were bought for $83.50?
1 solutions

Answer 48222 by checkley71(8403) About Me  on 2007-01-23 22:02:40 (Show Source):
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C+A=21 & 550*A+350*C=8350
C=21-A
550A+350(21-A)=8350
550A+7350-350A=8350
200A=8350-7350
200A=1000
A=1000/200
A=5 ANSWER FOR NUMBER OF ADULT TICKETS SOLD
21-5=16 ANSWER FOR CHILDREN TICKETS SOLD
PROOF
550*5+350*16=8350
2750+5600=8350
8350=8350


Mixture_Word_Problems/67819: A liter of cream has 9.2% butterfat. How much skim milk containing 2% butterfat should be added to the cream to obtain a maxture of 6.4% butterfat?
1 solutions

Answer 48219 by checkley71(8403) About Me  on 2007-01-23 21:53:50 (Show Source):
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1*.092+.02X=.064(1+X)
.092+.02X=.064+.064X
.02X-.064X=.064-.092
-.044X=-.028
X=-.028/-.044
X=.6363 LITERS OF 2% IS NEEDED
PROOF
.092+.02*.6363=.064(1.6363)
.092+.012726=.10472
.10472=.10472


Linear_Equations_And_Systems_Word_Problems/67820: my problem is: Luke has $5.00 more than Sam, together they have $73.00. How much does each have. Explain the equation.
I know the answer is $34.00 and $39.00, but i don't know how to write it out.
Thank you
1 solutions

Answer 48217 by checkley71(8403) About Me  on 2007-01-23 21:46:23 (Show Source):
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X+(X+5)=73
X+X+5=73
2X=73-5
2X=68
X=68/2
X=34 ANSWER FOR SAM
34+5=39 FOR LUKE
PROOF
34+39=73
73=73


Linear_Algebra/67792: A farmer normally plows a rectangular field 80ft by 120 ft. This year the farmer wants to expand the area of the field by 20%, by extending the width and length of the plowed area an equal amount. How much wider and longer should the farmer plow the field to obtain a 20% increase in area?
1 solutions

Answer 48215 by checkley71(8403) About Me  on 2007-01-23 21:42:40 (Show Source):
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CURRENT AREA=80*120=9600
TO INCREASE THIS AREA BY 20% IT MUST BE 9600*1.2=11520
THUS (80+X)(120+X)=11520
9600+120X+80X+X^2=11520
X^2+200X+9600-11520=0
X^2+200X-1920=0
USING THE QUADRATIC EQUATION WE GET
X=(-B+-SQRT[B^2-4AC])/2A
X=(-200+-SQRT[200*200-4*1*-1920])/2*1
X=(-200+-SQRT[40000+7680])/2
X=(-200+-SQRT47680])/2
X=(-200+-218.3578)/2
X=-200+218.3578)/2
X=18.3578/2
X=9.17875 ANSWER.


Graphs/67796: Solve by graphing.
x + y = 3
x - y = 1
I did:
x + y = 3 y = -x + 3 m = -1, 6 = 3
x - y = 1 -y = -x + 1 m = -1, 6 = 1
on my graph they coincided with each other instead of intersecting which is how the answer reads. (2,1)
Where did I go wrong?
Thanks a lot. Kyle
1 solutions

Answer 48211 by checkley71(8403) About Me  on 2007-01-23 21:27:13 (Show Source):
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X+Y=3
Y=-X+3
--------------
X-Y=1
-Y=-X+1
Y=X-1 this is where you made your mistake. you neglected to change -y to +y by multiplying the equation by -1.
also you have a 6 instead of a y in your answer.
-------------
graph%28+300%2C+200%2C+-6%2C+5%2C+-5%2C+5%2C+y+=+-x+%2B3%2C+y+=+x+-1%29 (graph 300x200 pixels, x from -6 to 5, y from -5 to 5, of TWO functions y = -x +3, y = x -1).


Equations/67803: This question is from textbook Glencoe Pre-Algebra
-4x/3=24

1 solutions

Answer 48210 by checkley71(8403) About Me  on 2007-01-23 21:17:30 (Show Source):
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-4X/3=24
-4X=72
X=72/-4
X=-18 ANSWER
PROOF
-4*-18/3=24
72/3=24
24=24


Equations/67807: 3/4n-3=9
1 solutions

Answer 48209 by checkley71(8403) About Me  on 2007-01-23 21:14:26 (Show Source):
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3/4N-3=9
3/4N=9+3
3/4N=12
3N=48
N=48/3
N=16 ANSWER
PROOF
3/4*16-3=9
12-3=9
9=9


Geometry_Word_Problems/67815: Given the formula P=-x/2 +75. Find the unit price
if seven items are sold.
1 solutions

Answer 48207 by checkley71(8403) About Me  on 2007-01-23 21:10:01 (Show Source):
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X REPRESENTS THE NUMBER OF ITEMS SOLD
THUS REPLACING X BY 7 IN THIS CASE WE GET
P=-7/2+75 NOW WE DIVIDE -7 BY 2 AND GET -3.5
P=-3.5+75 NOW WE SUBTRACT THE 3.5 FROM 75 AND WE GET
P=71.5 WHICH IS THE PRICE WHEN 7 UNITS ARE SOLD.
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DOES THIS HELP EXPLAIN THE METHOD USED TO SOLVE THIS PROBLEM?