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Recent problems solved by 'checkley71'
checkley71 answered: 8399 problems
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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) on 2007-12-17 19:14:54 (Show Source):
You can put this solution on YOUR website!.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
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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) on 2007-12-17 19:06:33 (Show Source):
You can put this solution on YOUR website!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.
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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) on 2007-12-17 19:02:19 (Show Source):
You can put this solution on YOUR website!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.
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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) on 2007-12-17 15:06:44 (Show Source):
You can put this solution on YOUR website!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
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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) on 2007-12-17 09:47:55 (Show Source):
You can put this solution on YOUR website!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.
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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) on 2007-12-17 09:31:50 (Show Source):
You can put this solution on YOUR website!.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
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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) on 2007-12-17 09:26:22 (Show Source):
You can put this solution on YOUR website!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
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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) on 2007-12-17 09:21:52 (Show Source):
You can put this solution on YOUR website!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
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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) on 2007-12-17 09:03:16 (Show Source):
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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) on 2007-12-16 21:23:18 (Show Source):
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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) on 2007-12-16 21:18:57 (Show Source):
You can put this solution on YOUR website!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.
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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) on 2007-12-16 20:56:43 (Show Source):
You can put this solution on YOUR website!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.
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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) on 2007-12-16 20:47:57 (Show Source):
You can put this solution on YOUR website!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
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