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the sum of two numbers is 21.Five times the first number added to 2 times the second number is 66.Find the two numbers.
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May 18, 2019
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the sum of two numbers is 21.Five times the first number added to 2 times the second number is 66.Find the two numbers.
Mathematics
college
Mujadid Mughal
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Mujadid Mughal
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Call them x and y. Thus
x + y = 21 and then
5x + 2y = 66
Multiply the top equation by two and subtract from the bottom one...
5x + 2y = 66
-(2x + 2y = 42)
and we get
3x = 24
x = 8
y = 21-x = 13
Matteo Merli
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May 20, 2019
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Matteo Merli
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a + b = 21 / x 5
5a + 5b = 105 -
5a + 2b = 66
--------------------
3b = 39
b = 39 : 3
b = 13
a = 31 -13
a = 18
Holger Leichsenring
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May 24, 2019
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Holger Leichsenring
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