document.write( "Question 202024: I can't understand what does it mean!
\n" ); document.write( "Mrs Brown, who is 51 years old, has a daughter 21 years old. How long will it be before mother is twice as old as her daughter \n" ); document.write( "

Algebra.Com's Answer #152279 by Earlsdon(6294) $\"\"$ $\"About$

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Let x = the number of years hence when Mrs. Brown (B, now 51) will be twice her daughter's age (D, now 21).
\n" ); document.write( "M = 51
\n" ); document.write( "D = 21
\n" ); document.write( "M+x = 2(D+x) Substitute M = 51 and D = 21.
\n" ); document.write( "51+x = 2(21+x)
\n" ); document.write( "51+x = 42+2x Subtract x from both sides.
\n" ); document.write( "51 = 42+x Subtract 42 from both sides.
\n" ); document.write( "9 = x
\n" ); document.write( "In 9 year's time, Mrs. Brown will be twice her daughter's age.
\n" ); document.write( "Check:
\n" ); document.write( "M+x = 2(D+x)
\n" ); document.write( "51+9 = 2(21+9)
\n" ); document.write( "60 = 2(30) OK!
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