document.write( "Question 949301: The age of a parent and child add up to 39 years,In 3years the parent will be 4 times as old as the child.find the age of the parent and the child. \n" ); document.write( "

Algebra.Com's Answer #579579 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

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let p = age of parent
\n" ); document.write( "let c = age of child
\n" ); document.write( ":
\n" ); document.write( "Write an equation for each statement
\n" ); document.write( ":
\n" ); document.write( "\" The age of a parent and child add up to 39 years,\"
\n" ); document.write( "p + c = 39:
\n" ); document.write( "or
\n" ); document.write( "p = (39-c); use this form for substitution
\n" ); document.write( ";
\n" ); document.write( "\"In 3years the parent will be 4 times as old as the child.\"
\n" ); document.write( "add 3 years to each
\n" ); document.write( "p + 3 = 4(c+3)
\n" ); document.write( "p + 3 = 4c + 12
\n" ); document.write( "p = 4c + 12 - 3
\n" ); document.write( "p = 4c + 9
\n" ); document.write( "Replace p with (39-c) from the 1st statement
\n" ); document.write( "39 - c = 4c + 9
\n" ); document.write( "39 - 9 = 4x + c
\n" ); document.write( "30 = 5c
\n" ); document.write( "c = 30/5
\n" ); document.write( "c = 6 yrs old is the child
\n" ); document.write( ":
\n" ); document.write( "I'll let you find the parent's age, check your solutions in the 2nd statement
\n" ); document.write( " \n" ); document.write( "

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