document.write( "Question 1175129: Age Practice Problem\r
\n" ); document.write( "\n" ); document.write( "The sum of the ages of Blake and Mackenzie is 68 years. 8 years ago, Blake's age was 3 times Mackenzie's age. How old is Blake now? \n" ); document.write( "

Algebra.Com's Answer #800678 by MathLover1(20850) $\"\"$ $\"About$

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\n" ); document.write( "let Blake ‘s age be $\"B\"$ and Mackenzie's age $\"M\"$ \r
\n" ); document.write( "\n" ); document.write( "if the sum of the ages of Blake and Mackenzie is $\"68\"$ years, we have\r
\n" ); document.write( "\n" ); document.write( " $\"B%2BM=68\"$ ....solve for $\"B\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"B=68-M\"$ ....eq.1\r
\n" ); document.write( "\n" ); document.write( " if $\"8\"$ years ago Blake's age was $\"3\"$ times Mackenzie's age, we have\r
\n" ); document.write( "\n" ); document.write( " $\"B-8=3%28M-8%29\"$ ....eq.2......substitute $\"B\"$
\n" ); document.write( " $\"68-M-8=3M-24\"$
\n" ); document.write( " $\"68%2B24-8=3M%2BM\"$
\n" ); document.write( " $\"84=4M\"$
\n" ); document.write( " $\"84%2F4=M\"$
\n" ); document.write( " $\"M=21\"$ \r
\n" ); document.write( "\n" ); document.write( "go to\r
\n" ); document.write( "\n" ); document.write( " $\"B=68-M\"$ ....eq.1....substitute $\"M\"$
\n" ); document.write( " $\"B=68-21\"$
\n" ); document.write( " $\"B=47\"$ \r
\n" ); document.write( "\n" ); document.write( "answer: Blake is $\"47\"$ years old now
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