SOLUTION: John is 12 years older than Susan. The sum of their age is 42. How old is each?

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Question 827513: John is 12 years older than Susan. The sum of their age is 42. How old is each?
Answer by TimothyLamb(4379) About Me  (Show Source):
You can put this solution on YOUR website!
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x = john
y = susan
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x = y + 12
x + y = 42
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put the system of linear equations into standard form:
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x - y = 12
x + y = 42
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copy and paste the above linear system in standard form into this matrix-method solver:
https://sooeet.com/math/system-of-linear-equations-solver.php
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solution:
x = john = 27
y = susan = 15
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system matrix
1 -1
1 1
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inverse of system matrix
0.5 0.5
-0.5 0.5
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determinant of system matrix = 2
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