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Mixture_Word_Problems/117351:
How much of a 80% alcohol solution must be mixed with 60 gallons of a 24% alcohol solution to obtain a solution that is 70% alcohol?
1 solutions

Answer 85379 by checkley71(8403) About Me  on 2007-12-17 19:14:54 (Show Source):
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.8x+.24*60=.7(x+60)
.8x+14.4=.7x+42
.8x-.7x=42-14.4
.1x=27.6
x=27.6/.1
x=276 gallons of 80% alcohol is required.
proof
.8*276+14.4=.7(276+60)
220.8+14.4=.7*336
235.2=235.2


Parallelograms/117370: This question is from textbook
seven of the angles of an octagon have measures of 90 degrees, 105 degrees, 125 degrees, 130 degrees, 150 degrees, 155 degrees, and 165 degrees. how do you find the measure of the 8th angle?
1 solutions

Answer 85378 by checkley71(8403) About Me  on 2007-12-17 19:06:33 (Show Source):
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the sum of all interior angles of an 8 sided figure is:
180(8-2)
180*6
1080
what you have are 7 of these angles which total:
90+105+125+130+150+155+165=920
so the missing angle must be:
1080-920=160 degrees.


Parallelograms/117368:
Find the measure of one of the interior angles of a regular polygon with twelve sides.
Thanks!
1 solutions

Answer 85377 by checkley71(8403) About Me  on 2007-12-17 19:02:19 (Show Source):
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the formula for this is:
t=180(12-2) t=the total of all 12 angles
t=180*10
t=1800
seeing as there are 12 angles we have
1800/12=150 degrees is the measurement of all interior angles.


Rational-functions/117333: will you please solve this problem it will be greatly appreciated
solve: (x)/(x-2)= 7/5
1 solutions

Answer 85362 by checkley71(8403) About Me  on 2007-12-17 16:17:21 (Show Source):
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X/(X-2)=7/5 CROSS MULTIPLY
7(X-2)=5X
7X-14=5X
7X-5X=14
2X=-14
X=-14/2
X=-7 ANSWER.
PROOF
7/(7-2)=7/5
7/5=7/5


Equations/117336:
4 1/3 divided by (-2 1/4)
1 solutions

Answer 85358 by checkley71(8403) About Me  on 2007-12-17 16:13:11 (Show Source):
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(4 1/3)/(-2 1/4)
(13/3)/(-9/4) NOW INVERT THE DENOMINATOR & MULTIPLY.
13/3*-4/9
-52/27 ANSWER.


test/117332: will you please solve this problem

solve: (9)/(m-5)<3
1 solutions

Answer 85357 by checkley71(8403) About Me  on 2007-12-17 16:09:48 (Show Source):
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9/(M-5)<3 CROSS MULTIPLY
3(M-5)>9
3M-15>9
3M>9+15
3M>24
M>24/3
M>8 ANSWER.
PROOF:
LET M=8.1
9/(8.1-5)<3
9/3.1<3
2.9<3


Polynomials-and-rational-expressions/117237: Factor.
12x^4y^3 + 16x^3y^3 – 20x^3y^4 i think i got this but want to make sure.
1 solutions

Answer 85355 by checkley71(8403) About Me  on 2007-12-17 16:04:05 (Show Source):
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12X^4Y^3+16X^3Y^3-20X^3Y^4
4X^3Y^3(4X+4-5Y) ANSWER.


Equations/117323: Divide.
3 '/' 12
-- ---
x^5 x^2
1 solutions

Answer 85352 by checkley71(8403) About Me  on 2007-12-17 15:39:48 (Show Source):
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(3/X^5)/(12/X^2) NOW INVERT THE DENOMINATOR & MULTIPLY.
(3/X^5)(X^2/12)
3X^2/12X^5
1/4X^3 ANSWER.


Polynomials-and-rational-expressions/117143: Simplify the expression. Write the reslut using positive exponents only.
5^-7x^-3y^2
____________
5^-4x^-6y^4
1 solutions

Answer 85351 by checkley71(8403) About Me  on 2007-12-17 15:17:36 (Show Source):
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5^-7/5^-4=5^(-7+4)=5^-3=1/5^3
X^-3/X^-6=X^(-3+6)=X^3
Y^2/Y^4=Y^(2-4)=Y^-2=1/Y^2
COMBINING THESE ELEMENTS WE HAVE:
X^3/5^3Y^2 OR X^3/125Y^2 ANSWER.


Linear-equations/117320: Hello I really need some help with this math problem it deal with Coordinate Geometry: Linear Equations in Two Variables.
What is the equation of the line that contains the points with (x,y) coordinates (-3,7) and (5,-1) ?
I don't have clue how to set this type of problem up, please help.
thanks

1 solutions

Answer 85349 by checkley71(8403) About Me  on 2007-12-17 15:06:44 (Show Source):
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FIRST YOU NEED TO FIND THE SLOPE:
SLOPE=(Y2-Y1)/(X2-X1)
SLOPE=(-1-7)/(5+3)
SLOPE=-8/8
SLOPE=-1
USING THE SLOPE (m) AND A SET OF (X,Y) VALUES IN THE LINE EQUATION Y=mX+b SOLVE FOR (b), THE Y INTERCEPT.
7=-1*-3+b
7=3+b
b=7-3
b=4
THUS THE EQUATION IS:
Y=-X+4


Quadratic_Equations/117290: Find two consecutive positive intergers such that the sum of their square is 85.

1 solutions

Answer 85320 by checkley71(8403) About Me  on 2007-12-17 09:58:46 (Show Source):
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X^2+(X+1)^2=85
X^2+X^2+2X+1=85
2X^2+2X+1-85=0
2X^2+2X-84=0
2(X^2+X-42)
2(X+7)(X-6)=0
X+7=0
X=-7 ANSWER.
X-6=0
X=6 ANSWER.
PROOF
6^2+7^2=85
36+49=85
85=85


Polynomials-and-rational-expressions/117145:
y2+11y=28
1 solutions

Answer 85319 by checkley71(8403) About Me  on 2007-12-17 09:54:23 (Show Source):
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Y^2+11Y=28
Y^2+11Y-28=0
USING THE QUADRATIC EQUATION:x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
WE GET
Y=(-11+-SQRT[11^2-4*1*-28])/2*1
Y=(-11+-SQRT[121+112])/2
Y=(-11+-SQRT[233)/2
Y=(-11+-15.26)/2
Y=(-11+15.26)/2
Y=4.26/2
Y=2.13 ANSWER.
Y=(-11-15.26)/2
Y=-26.26/2
Y=-13.13 ANSWER.


Coordinate-system/117147: determine whether the lines through the paris of points are parallel, perpendicular, of neither
3x-12y=11
64x+12y=-18
1 solutions

Answer 85318 by checkley71(8403) About Me  on 2007-12-17 09:47:55 (Show Source):
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3X-12Y=11 OR -12Y=-3X+11 OR Y=-3X-12+11/-12 0R Y=X/4-11/12 SLOPE=1/4
64X+12Y=-18 OR 12Y=-64X-18 OR Y=-64X/12-18/12 OR Y=-16X/3-3/2 SLOPE=-16/3
THESE TWO LINES ARE NEITHER PARALLEL NOR PERPENDICULAR.


Travel_Word_Problems/117198:
a cruise boat travels 24 miles downstreamin 3 hoursand returns to its starting point upstream in 6 hours. find the speed of the stream.
1 solutions

Answer 85317 by checkley71(8403) About Me  on 2007-12-17 09:42:00 (Show Source):
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24/3=8 MPH GOING DOWNSTREAM.
24/6=4 MPH GOING UPSTREAM.
8-S=4+S
-2S=-4
S=-4/-2
S=2 IS THE SPEED OF THE STREAM.
PROOF
24/(8-2)=24/(4+2)
24/6=24/6
4=4


Linear-systems/117263:
A Chemist ahs 25% and a 50% acid soultion. How much of each soultion should be used to form 200 ml of a 35% acid soultion.
1 solutions

Answer 85315 by checkley71(8403) About Me  on 2007-12-17 09:31:50 (Show Source):
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.25X+.50(200-X)=200*.35
.25X+100-.50X=70
-.25X=70-100
-.25X=-30
X=-30/-.25
X=120 ML OF 25% ACID IS REQUIRED.
200-120=80 ML OF 50% ACID IS ALSO REQUIRED.
PROOF
.25*120+.50*80=70
30+40=70
70=70


Linear-systems/117264:
The length of a rectangle is 3 m more than twice its width, IF the perimeter of the rectangle is 42 m, find the dimensions of the rectangle.
1 solutions

Answer 85314 by checkley71(8403) About Me  on 2007-12-17 09:26:22 (Show Source):
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L=2W+3
42=2(2W+3)+2W
42=4W+6+2W
42=6W+6
6W=42-6
6W=36
W=36/6
W=6M FOR THE WIDTH.
L=2*6+3
L=12+3
L=15M FOR OF THE LENGTH.
PROOF
42=2*15+2*6
42=30+12
42=42


Linear-systems/117265: Adult tickets for a play cost $11 and child tickets cost $10. If there were 23 people at a perfromance and the theater collected $246 from tickets sales, how mant childern attended the play?
1 solutions

Answer 85313 by checkley71(8403) About Me  on 2007-12-17 09:21:52 (Show Source):
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A+C=23 OR A=23-C FOR THE NUMBER OF TICKETS SOLD.
11A+10C=246
NOW REPLACE A WITH(23-C) IN THE SECOND EQUATION & SOLVE FOR C
11(23-C)+10C=246
253-11C+10C=246
-C=246-253
-C=-7
C=7 CHILDREN'S TICKETS WERE SOLD. (NO IDEA HOW MANY CHILDREN ATTENDED)
23-7=16 ADULT TICKETS SOLD.
PROOF
11*16+10*7=246
176+70=246
246=246


Linear-systems/117266:
Thw equation y=0.10x +200 describes the award money in a recycling contest. What are the slope and the y-intercept for this equation.
1 solutions

Answer 85312 by checkley71(8403) About Me  on 2007-12-17 09:15:27 (Show Source):
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Y=0.10X+200
THE LINE FORMULA IS Y=mX+b WHERE (m)=SLOPE & (b)=Y INTERCEPT.
THE SLOPE=0.10
THE Y INTERCEPT=200


Radicals/117270:
2sqrtx=4sqrt3
1 solutions

Answer 85311 by checkley71(8403) About Me  on 2007-12-17 09:12:35 (Show Source):
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2SQRTX=4SQRT3 SQUARING BOTH SIDES.
(2*2)(SQRTX*SQRTX)=(4*4)(SQRT3*SQRT3)
4X=16*3
4X=48
X=48/4
X=12 ANSWER.
PROOF
2SQRT12=4SQRT3
2SQRT4*3=4SQRT3
(2*2)SQRT3=4SQRT3
4SQRT3=4SQRT3


expressions/117280: simplify

54m third power/9m fourth power
1 solutions

Answer 85310 by checkley71(8403) About Me  on 2007-12-17 09:05:38 (Show Source):
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54M^3/9M^4
6/M ANSWER.


Inequalities/117285: Solve for y:

y + 1/2 = -1/3 (x + 1/2)
What I have done:
y + 1/2 = -1/3x + 1/2 * -1/3
y + 1/2 = - 1/3x -2/6 (THIS SHOULD BE -1/6)
y + 1/2 - 1/2 = - 1/3 x - 2/6 - 1/2
y = - 1/3x + 10/12
y = - 1/3x + 5/6
y = - 1/3x / -1/3 + 5/6 / -1/3
y = x -15/6
1 solutions

Answer 85308 by checkley71(8403) About Me  on 2007-12-17 09:03:16 (Show Source):
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Y+1/2=-1/3(X+1/2)
Y+1/2=-1/3X-1/3*1/2
Y+1/2=-1/3X-1/6
Y=-1/3X-1/6-1/2
Y=-1/3X-4/6
Y=-1/3X-2/3
Y=-X/3-2/3
Y=(-X-2)/3 ANSWER.


Money_Word_Problems/117248: ms. jones has been given a loan of $2500 for 1 year. if the interest charged is $275, what is the interest rate on the loan?
1 solutions

Answer 85285 by checkley71(8403) About Me  on 2007-12-16 21:28:21 (Show Source):
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275/2500=.11 OR 11% INTEREST.


Percentage-and-ratio-word-problems/117250: a survey of 400 people found that 66 were left-handed. What percent of those surveyed were left-handed?
1 solutions

Answer 85284 by checkley71(8403) About Me  on 2007-12-16 21:26:42 (Show Source):
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66/400=.165 OR 16.5 % WERE LEFT HANDED.


Percentage-and-ratio-word-problems/117251: the electricity costs of a business decreased from $12,000 one year to $10,920 the next. what is the rate of decrease?
1 solutions

Answer 85283 by checkley71(8403) About Me  on 2007-12-16 21:25:15 (Show Source):
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(12,000-10,920)/12,000=1080/12,000.09 OR 9% ANNUAL DECREASE.


Probability-and-statistics/117140: Given a single deck of cards, what is the probability of drawing either a king or a diamond? Hint – There are four kings in a deck and 13 diamonds. There are a total of 52 cards in a single deck.
1 solutions

Answer 85282 by checkley71(8403) About Me  on 2007-12-16 21:23:18 (Show Source):
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(4+12)/52=16/52=4/13 OR.3077 IS THE PROBABILITY OF DRAWING A KING OR A DIAMOND.
THERE ARE 4 KINGS (1 OF WHICH IS A DIAMOND)


Miscellaneous_Word_Problems/117136: After surveying 50 students in Mr. Paul's math class, it is determined that 18 take pre-cal and 19 take statistics.Given that information, what is the minimum number of sudents in his class who take both pre-cal and statistics?
1 solutions

Answer 85281 by checkley71(8403) About Me  on 2007-12-16 21:18:57 (Show Source):
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THE ANSWER IS 0.
PRE CAL=18
STAT=19
THUS YOU HAVE A TOTAL OF 37 STUDENTS THAT COULD TAKE ONLY ONE OF THESE SUBJECTS AND ANOTHER 50-37=13 WHO TAKE NEITHER COURSE.


Miscellaneous_Word_Problems/117132: A poker hand consists of five cards dealt from a deck of 52. How many diferent poker hands are possible?
1 solutions

Answer 85280 by checkley71(8403) About Me  on 2007-12-16 21:14:01 (Show Source):
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52*51*50*49*48=311,875,200 POSSIBLE DIFFERENT HANDS CAN BE DEALT WITH 5 CARDS.


Money_Word_Problems/117196: Ace bought a jacket for $36. This was a reduction in price of 21%. What was the price of the jacket?
1 solutions

Answer 85278 by checkley71(8403) About Me  on 2007-12-16 21:06:19 (Show Source):
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X-.21X=36
.79X=36
X=36/.79
X=$45.57 WAS THE ORIGINAL PRICE BEFORE THE REDUCTION.


Polynomials-and-rational-expressions/117226: I hate word problems, and have a hard enough time figuring them out let alone making one up. How should I give an example of using polynomials in “real life” applications?
1 solutions

Answer 85277 by checkley71(8403) About Me  on 2007-12-16 20:56:43 (Show Source):
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HERE'S ONE.
GAS IS $3.00 PER GALLON, YOUR CAR AVERAGES 25 MPG AND YOU ARE PLANNING A TRIP OF 3,000 MILES. HOW MUCH GAS MONEY SHOULD YOU TAKE ON THE TRIP?
25/3000=3/X (X BEING THE AMOUNT OF MONEY NEEDED). NOW CROSS MULTIPLY
25X=3*3000
25X=9000
X=9000/25
X=$360 IS THE COST OF GAS @ $3.00 PER GALLON, TO TRAVEL 3,000 MILES, IN A CAR THAT GETS 25 MPG.
$360 WILL BUY YOU 360/3=120 GALLONS OF GAS
120 GALLONS OF GAS TIMES 25 MPG=3000 MILES.


Miscellaneous_Word_Problems/117228: Solve.
Mark drove 250 miles to visit Sandra. Returning by a shorten route, he found that the trip was only 225 miles, but traffic slowed his speed by 5 miles. If the two trips took exactly the same time, what was his rate on the return trip?
1 solutions

Answer 85276 by checkley71(8403) About Me  on 2007-12-16 20:47:57 (Show Source):
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250/R=225/(R-5) NOW CROSS MULTIPLY
250(R-5)=225R
250R-1250=225R
250R-225R=1250
25R=1250
R=1250/25
R=50 MPH IS THE SPEED OF THE FIRST TRIP
50-5=45 MPH FOR THE RETURN TRIP.
PROOF
250/50=225/45
5=5


Polynomials-and-rational-expressions/117229: Find all positive values for k for which each of the following can be factored.
x^2+x-k
Thanks
1 solutions

Answer 85275 by checkley71(8403) About Me  on 2007-12-16 20:43:12 (Show Source):
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k can be any number that has 2 factors that differ by 1'
examples are:
2*3=6 (x^2+x-6)=(x-2)(x+3)
7*8=56 (x^2+x-56)=(x-7)(x+8)
9*10=90 (x^2+x-90)=(x+10)(x-9)