Question 947559
Let {{{ s }}} = son's age now
Let {{{ f }}} = father's age now
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(1) {{{ s - 5 + f - 5 = 46 }}}
(2) {{{ f + 8 = 2*( s + 8 ) }}}
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(1) {{{ f + s = 46 + 10 }}}
(1) {{{ f + s = 56 }}}
and
(2) {{{ f + 8 = 2s + 16 }}}
(2) {{{ f - 2s = 16 - 8 }}}
(2) {{{ f - 2s = 8 }}}
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Subtract (2) from (1)
(1) {{{ f + s = 56 }}}
(2) {{{ -f + 2s = -8 }}}
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{{{ 3s = 48 }}}
{{{ s = 16 }}}
and
(1) {{{ f + s = 56 }}}
(1) {{{ f + 16 = 56 }}}
(1) {{{ f = 40 }}}
At present, the father is 40
check:
(2) {{{ f + 8 = 2*( s + 8 ) }}}
(2) {{{ 40 + 8 = 2*( 16 + 8 ) }}}
(2) {{{ 48 = 2*24 }}}
(2) {{{ 48 = 48 }}}
OK
(1) {{{ f + s = 56 }}}
(1) {{{ 40 + 16 = 56 }}}
(1) {{{ 56 = 56 }}}
OK