First Digit = x
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document.write( "Second Digit = y
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document.write( "x+y=14
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document.write( "x=2y-4 (This comes from the relationship explained.)
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document.write( "Substitute the value of x, in terms of y, from the second equation into the first.
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document.write( "2y-4+y=14 ---> 3y=18 (combined y's, added 4 to both sides.)---> y = 6 (divided both sides by 3.)
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document.write( "x+6=14 (subtract 6 from both sides.) x=8\r
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