15x + 11y = 309
x + y = 23
15x + 15y = 15*23
Eliminate x to get
4y = 15*23 - 309
y = 9
answer b
2007-06-02 06:16:54
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answer #1
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answered by Dr D 7
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Substitution Method
let
x = children
y = adults
23 = total children and adults
11x = cost of children tickets
15 = cost of adults tickets
309 = total collected
- - - - - - - - - - -
x + y = 23- - - - - - - - - -Equation 1
11x + 15y = 309- - - - -Equation 2
- - - - - - - - - - - -
x + y = 23
x + y - x = - x + 23
y = - x + 23
Substitute the y value into equation 2
- - - - - - - - - - - -
11x + 15y = 309
11x + 15(- x + 23) = 309
11x +(- 15x + 345) = 309
11x - 15x + 345 = 309
- 4x + 345 = 309
- 4x + 345 - 345 = 309 - 345
- 4x = - 36
- 4x/-4 = - 36/-4
x = - 36/-4
x = 9. . . .Number of Children
Insert the x value into equation 1
- - - - - - - - -
x + y = 23
9 + y = 23
9 + y = 9 = 23 - 9
y = 14. . . .Number of adults
Insert the y value into equation 1
- - - - - - - - - -
Check for equation 1
x + y = 23
9 + 14 = 23
23 = 23
- - - - - - - - -
Check for equation 2
11x + 15y = 309
11(9) + 15(14) = 309
99 + 210 = 309
309 = 309
- - - - - - - - - -
Both equations balance
The solution set { 9, 14 }
- - - - - - - - - - -s-
2007-06-02 07:20:55
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answer #2
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answered by SAMUEL D 7
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First set up equation, adults equal x and children equal y.
So:
X+Y=23 people at performance
15X+11Y=309 dollars collected.
Use substitution for this one, so -
Y=23-X
So where ever you see Y in the second equation, put in 23-X -
15X+11(23-X)=309 or 15X+253-11X=309
Combine like terms -
4X=56
Divide by 4 on each side
X=14
Plug in X for the first equation -
14+Y=23
Subtract 14 from each side
Y=23-14
There were 9 children at the play. Your answer is B.
2007-06-02 06:44:19
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answer #3
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answered by Life Is Beautiful at Sixx: A.M. 3
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14 Adults and 9 Children
you form the equation
15(x)+11(23-x)=309 then solve
2007-06-02 06:19:59
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answer #4
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answered by Anonymous
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let X be number of adults
let Y be number of childs
cost of adult tickets is 15$ so total value = 15X
cost of child tickets is 11$ so total value = 11Y
Total theater collection will be 15X+11Y = 309
Total people who attended is X+Y = 23
15X+15Y = 345 (multiply by 15 the equation (x+y=23))
15X + 11Y = 309
- - - (subtract the two equation/elimination method)
------------------------
4Y = 36
Y = 36/4 = 9
9 children attended the theatre (ANSWER)
2007-06-02 06:20:49
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answer #5
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answered by Sam 2
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Adults (A) and Children (C) total 20 people attending the performance. In equation this is A + C = 20 A cost is 17 C cost is 5. 17A + 5C = 280. Using substitution A = 20 - C. So 17(20 - C) + 5C = 280. This is 340 - 17C + 5C = 280. This in turn is 60 = 12C so C = 5. Therefore 15 adults and 5 children attended the play.
2016-04-01 11:43:12
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answer #6
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answered by Anonymous
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let there be a adults and c children
15a + 11c = 309
cost of adult times no of adults + cost of child times no of children = 309
a + c = 23
total no people = 23
a = 23-c
substitute
15(23-c) + 11c = 309
345 - 15c + 11c = 309
36 = 4c
c = 9
substitute in a + c = 23
a = 23 - 9
a = 14
14 adults and 9 children attended
2007-06-02 06:41:43
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answer #7
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answered by rosie recipe 7
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let x b the no of adults and y be the children
x + y = 23
15x + 11y = 309
solving the second eq using first eq i.e. x = 23-y
y = 9
and x = 23-9 = 14
2007-06-02 06:18:33
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answer #8
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answered by me_poori 2
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b) 9
A= adult tickets B= child tickets
15A + 11C= 309
A+C =23
A=23-C
15(23-C) +11C=309
solve and C= 9
2007-06-02 06:19:25
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answer #9
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answered by Jo W 1
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let the number of adults be a, and the number of children be c.
Then, from the question,
$15a + $11c = $309
and, the total number of people, a+c = 23
then, a= 23-c. Replacing a,
15(23-c) + 11c = 309
345 - 4c = 309
4c = 36
c=9
therefore the answer is b) 9 children.
2007-06-02 06:19:33
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answer #10
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answered by shekum 2
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