Question 566620
Let {{{ a }}} = Alfred's age now
{{{ a - 6 }}} = Alfred's age 6 yrs ago
Let {{{ b }}} = his brother's age now
{{{ b - 6 }}} = brother's age 6 yrs ago
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given:
(1) {{{ a = 3b }}}
(2) {{{ ( a - 6 ) + ( b - 6 ) = a }}}
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(2) {{{ a + b - 12 = a }}}
Subtract {{{ a }}} from both sides
(2) {{{ b - 12 = 0 }}}
(2) {{{ b = 12 }}}
and
(1) {{{ a = 3b }}}
(1) {{{ a = 36 }}}
Alfred is 36 now, and
his brother is 12 now