Question 762825
Let {{{ f }}} = father's age now
Let {{{ s }}} = son's age now
given:
(1) {{{ f = 3s }}}
(2) {{{ f + 12 = 2*( s + 12 ) }}}
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(2) {{{ f + 12 = 2s + 24 }}}
(2) {{{ f - 2s = 12 }}}
Substitute (1) into this
(2) {{{ 3s - 2s = 12 }}}
(2) {{{ s = 12 }}}
and, since
(1) {{{ f = 3s }}}
(1) {{{ f = 3*12 }}}
(1) {{{ f = 36 }}}
The son is 12 and the father is 36
check:
(2) {{{ f + 12 = 2*( s + 12 ) }}}
(2) {{{ 36 + 12 = 2*( 12 + 12 ) }}}
(2) {{{ 48 = 2*24 }}}
(2) {{{ 48 = 48 }}}
OK