Answer:
- number of 12 dollar tickets = 70
- number of 10 dollar tickets = 220
- number of 8 dollar tickets = 200
Step-by-step explanation:
Givens
- Let the 8 dollar ticket number = x1
- Let the 10 dollar ticket number = x2
- Let the 12 dollar ticket number = x3
Equations
- x1 + x2 + x3 = 490
- (x1 + x2) = 6*x3
- x1*8 + x2*10 * x3*12 = 4640
Solution
You can get x3 right away.
x1 + x2 + x3 = 490 Substitute 6*x3 for x1 + x2
6*x3 + x3 = 490 Combine
7*x3 = 490 Divide by 7
7*x3/7 = 490/7 Do the division
x3 = 70 Answer x3
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x1 + x2 + 70 = 490 Let x3 = 70
x1 + x2+70-70=490-70 Subtract 70
x1 + x2 = 420
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8x1 + 10x2 + 12x3 = 4640 Use the third equation to get an amount for x1,x2
8x1 + 10x2 + 12*70 = 4640
8x1 + 10x2 + 840 = 4640 Subtract 840
8x1 + 10x2 = 4640 - 840 Combine
8x1 + 10x2 = 3800
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8x1 + 8x2 = 420*8
8x1 + 8x2 = 3360
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8x1 + 10x2 = 3800
8x1 + 8x2 = 3360 Subtract
2*x2 = 440
2*x2/2 = 440/2
x2 = 220
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x1 + x2 + x3 = 490
x1 + 220 + 70 = 490
x1 + 290 = 490
x1 = 200