document.write( "Question 402002: A is eleven times as old as B. In a certain number of years A will be five times as old as B, and five years after that she will be three times as old as B. How old are they now? \n" ); document.write( "
Algebra.Com's Answer #284421 by ankor@dixie-net.com(22740)\"\" \"About 
You can put this solution on YOUR website!
Write an equation for each statement, simplify each equation:
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\n" ); document.write( "\"A is eleven times as old as B.\"
\n" ); document.write( "a = 11b
\n" ); document.write( ":
\n" ); document.write( "\"In a certain number of years A will be five times as old as B,\"; y = no. of yrs
\n" ); document.write( "a + y = 5(b+y)
\n" ); document.write( "a + y = 5b + 5y
\n" ); document.write( "a = 5b + 5y - y
\n" ); document.write( "a = 5b + 4y
\n" ); document.write( "replace a with 11b
\n" ); document.write( "11b = 5b + 4y
\n" ); document.write( "11b - 5b = 4y
\n" ); document.write( "6b = 4y
\n" ); document.write( "6b - 4y = 0
\n" ); document.write( ":
\n" ); document.write( "\"five years after that she will be three times as old as B.\" That's y+5 yrs
\n" ); document.write( "a + y + 5 = 3(b + y + 5)
\n" ); document.write( "a + y + 5 = 3b + 3y + 15
\n" ); document.write( "a = 3b + 3y - y + 15 - 5
\n" ); document.write( "a = 3b + 2y + 10
\n" ); document.write( "replace a with 11b
\n" ); document.write( "11b = 3b + 2y + 10
\n" ); document.write( "11b - 3b = 2y + 10
\n" ); document.write( "8b = 2y + 10
\n" ); document.write( "8b - 2y = 10
\n" ); document.write( ":
\n" ); document.write( "Multiply above equation by -2, add to the 1st equation
\n" ); document.write( "-16b + 4y = -20
\n" ); document.write( " 6b - 4y = 0
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\n" ); document.write( "-10b = -20
\n" ); document.write( "b = 2 yrs old
\n" ); document.write( "Find a
\n" ); document.write( "a = 11(2)
\n" ); document.write( "a = 22 yrs old
\n" ); document.write( ":
\n" ); document.write( "We can say their present ages are: A=22; B=2
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\n" ); document.write( ":
\n" ); document.write( "To check our our solutions, Find y
\n" ); document.write( "6(2) - 4y = 0
\n" ); document.write( "12 - 4y = 0
\n" ); document.write( "-4y = -12
\n" ); document.write( "y = 3 yrs is that \"certain number of years\"
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\n" ); document.write( "Check in the statement:
\n" ); document.write( "\"In a certain number of years A will be five times as old as B,
\n" ); document.write( "22 + 3 = 5(2 + 3)
\n" ); document.write( "25 = 25
\n" ); document.write( ":
\n" ); document.write( "You can check the solutions in the 3rd statement:
\n" ); document.write( "\"five years after that she will be three times as old as B.\" That's y+5 yrs\"\r
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