document.write( "Question 1173233: Hey can you please help me with this word problem ASAP? Five times my age augmented by twice my sisters age is equal to sixty-four. Likewise, triple her age decreased by twice my age is equal to one. How old were each of us last year? \n" ); document.write( "
Algebra.Com's Answer #798442 by MathTherapy(10552)\"\" \"About 
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\n" ); document.write( "Hey can you please help me with this word problem ASAP? Five times my age augmented by twice my sisters age is equal to sixty-four. Likewise, triple her age decreased by twice my age is equal to one. How old were each of us last year?
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IGNORE Theo's setup of this problem. 
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document.write( "Never solve for a variable unless asked to use SUBSTITUTION or if one of the equations has variable coefficients, 1 or - 1.
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document.write( "Let my age and my sister's be I, and S, respectively
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document.write( "Then we get: 5I + 2S = 64 ------ eq (i)
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document.write( "Also, - 2I + 3S = 1 ------- eq (ii)
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document.write( "10I + 4S = 128 ------- Multiplying eq (i) by 2 ------ eq (iii) 
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document.write( "- 10I + 15S = 5 ------ Multiplying eq (ii) by 5 ----- eq (iv)
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document.write( "19S = 133 ----- Adding eqs (iii) & (iv)
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document.write( "Sister's age, or \"highlight_green%28matrix%281%2C5%2C+S%2C+%22=%22%2C+133%2F19%2C+%22=%22%2C+7%29%29\"
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document.write( "5I + 2(7) = 64 ------ Substituting 7 for S in eq (i)
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document.write( "5I + 14 = 64
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document.write( "5I = 50
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document.write( "My age, or \"highlight_green%28matrix%281%2C5%2C+I%2C+%22=%22%2C+50%2F10%2C+%22=%22%2C+10%29%29\"
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document.write( "I'll now leave you to find both ages, a year ago! \n" );
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