document.write( "Question 1012058: In 1950 Roberto was four times as old as Juan. In 1955 Roberto was three times as old as Juan. How old was Roberto when Juan was born?\r
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Algebra.Com's Answer #627901 by ikleyn(52798) $\"\"$ $\"About$

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\n" ); document.write( "In 1950 Roberto was four times as old as Juan. In 1955 Roberto was three times as old as Juan. How old was Roberto when Juan was born?
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document.write( "In 1950: R = 4*J         (1)\r\n" );
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document.write( "where R is Roberto's age in 1950, and J is Juan's age in 1950, at the moment of comparison. \r\n" );
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document.write( "In 1955, 5 years later: \r\n" );
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document.write( "R + 5 = 3*(J + 5).       (2)\r\n" );
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document.write( "Solve these two equations. Substitute (1) into (2) and simplify.\r\n" );
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document.write( "4J + 5 = 3J + 15,\r\n" );
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document.write( "J = 15 - 5 = 10.\r\n" );
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document.write( "So, in 1950 Juan was 10 years old. Roberto was 40 years old in 1950.\r\n" );
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document.write( "Thus Roberto is 30 years older than Juan.\r\n" );
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document.write( "Hence, Roberto was 30 years old when Juan was born.\r\n" );
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