document.write( "Question 572761: jan is twice as old as jake. the sum of their ages is 5 less than twice of Jan's age. How old are jane ane jake? \n" ); document.write( "

Algebra.Com's Answer #368821 by mathsmiles(68) $\"\"$ $\"About$

You can put this solution on YOUR website!
Too bad they didn't have different initials or we could use those for our variable names. Instead, let's use X and Y.
\n" ); document.write( "Jan's current age = X
\n" ); document.write( "Jake's current age = Y\r
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\n" ); document.write( "\n" ); document.write( "Jan is twice as old as Jake:
\n" ); document.write( "X = 2Y\r
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\n" ); document.write( "\n" ); document.write( "The sum of their ages (X + Y) is 5 less than twice Jan's age (2X)
\n" ); document.write( "(X + Y) + 5 = 2X\r
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\n" ); document.write( "\n" ); document.write( "Let's substitute for X in the above equation using X=2Y from before:
\n" ); document.write( "((2Y) + Y) + 5 = 2(2Y) We can remove the parens from the left side since it's all addition:
\n" ); document.write( "2Y + Y + 5 = 2(2Y)
\n" ); document.write( "combining terms:
\n" ); document.write( "3Y + 5 = 4Y
\n" ); document.write( "Subtract 3Y from both sides:
\n" ); document.write( "5 = Y\r
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\n" ); document.write( "\n" ); document.write( "Jake is 5. Since Jan is twice Jake's age, she's 10.\r
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\n" ); document.write( "\n" ); document.write( "Checking our answer:
\n" ); document.write( "The sum of their ages (5 + 10 = 15) is 5 less than twice Jan's age (20).
\n" ); document.write( "15 is 5 less than 20.
\n" ); document.write( "15 = 20 - 5
\n" ); document.write( "15 = 15 Correct! \n" ); document.write( "

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