document.write( "Question 941572: Bob's father is 3 times old as Bob. 4 years ago, he was 4 times older. How old is Bob? \n" ); document.write( "
Algebra.Com's Answer #573972 by srinivas.g(540)\"\" \"About 
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let present age of bob be x years
\n" ); document.write( " bob's father = 3times bob's age
\n" ); document.write( " = 3x
\n" ); document.write( "4 years ago, age of bob = x-4
\n" ); document.write( " 4 years ago, age of father = 3x-4
\n" ); document.write( " 4 years afo father's age = 34 times bob's age
\n" ); document.write( " 3x-4 =4(x-4)
\n" ); document.write( " 3x-4 = 4x-16
\n" ); document.write( " 16+3x-4= 4x
\n" ); document.write( " 12 +3x=4x
\n" ); document.write( " 12 = 4x-3x
\n" ); document.write( " 12 =x
\n" ); document.write( "Result: age of bob(x)= 12 years\r
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