document.write( "Question 504603: shane is twice as old as his daughter in 42 years the ratio of thir ages will be 4:3 what is the daughter's current age? \n" ); document.write( "

Algebra.Com's Answer #339652 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"s\"$ = Shane's age now
\n" ); document.write( "Let $\"d\"$ = Daughter's age now
\n" ); document.write( "given:
\n" ); document.write( "(1) $\"+s+=+2d+\"$
\n" ); document.write( "(2) $\"%28+s+%2B+42%29+%2F+%28d+%2B+42%29+=+4%2F3+\"$
\n" ); document.write( "----------------------
\n" ); document.write( "I have 2 equations and 2 unknowns, so
\n" ); document.write( "it should be solvable
\n" ); document.write( "Multiply both sides of (2) by $\"+3%2A%28+d+%2B+42+%29+\"$
\n" ); document.write( "(2) $\"+3%2A%28+s+%2B+42+%29+=+4%2A%28+d+%2B+42+%29+\"$
\n" ); document.write( "(2) $\"+3s+%2B+126+=+4d+%2B+168+\"$
\n" ); document.write( "(2) $\"+3s+-+4d+=+42+\"$
\n" ); document.write( "Substitute (1) into (2)
\n" ); document.write( "(2) $\"+3%2A2d+-4d+=+42+\"$
\n" ); document.write( "(2) $\"+2d+=+42+\"$
\n" ); document.write( "(2) $\"+d+=+21+\"$
\n" ); document.write( "His Daughter's age is 21
\n" ); document.write( "check:
\n" ); document.write( "(2) $\"%28+s+%2B+42%29+%2F+%28d+%2B+42%29+=+4%2F3+\"$
\n" ); document.write( "(2) $\"%28+s+%2B+42%29+%2F+%2821+%2B+42%29+=+4%2F3+\"$
\n" ); document.write( "(2) $\"+%28+s+%2B+42+%29+%2F+63+=+4%2F3+\"$
\n" ); document.write( "Multiply both sides by $\"63\"$
\n" ); document.write( "(2) $\"+s+%2B+42+=+21%2A4+\"$
\n" ); document.write( "(2) $\"+s+=+84+-+42+\"$
\n" ); document.write( "(2) $\"+s+=+42+\"$
\n" ); document.write( "Shane is twice as old as his daughter -OK \n" ); document.write( "

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