Question 592116
Let {{{ f }}} = Father's age now
Let {{{ s }}} = Son's age now
given:
(1) {{{ f - 5 = 3*( s - 5 ) }}}
(2) {{{ f + 5 = 2*( s + 5 ) }}}
--------------------
(1) {{{ f - 5 = 3s - 15 }}}
(1) {{{ 3s - f = 10 }}}
and
(2) {{{ f + 5 = 2s + 10 }}}
(2) {{{ 2s - f = -5 }}}
Subtract (2) from (1)
(1) {{{ 3s - f = 10 }}}
(2) {{{ -2s + f = 5 }}}
{{{ s = 15 }}}
and
(1) {{{ 3s - f = 10 }}}
(1) {{{ 3*15 - f = 10 }}}
(1) {{{ 45 - f = 10 }}}
(1) {{{ f = 45 - 10 }}}
(1) {{{ f = 35 }}}
Father is 35 and Son is 15
check:
(1) {{{ f - 5 = 3*( s - 5 ) }}}
(1) {{{ 35 - 5 = 3*( 15 - 5 ) }}}
(1) {{{ 30 = 3*10 }}}
(1) {{{ 30 = 30 }}}
OK
(2) {{{ f + 5 = 2*( s + 5 ) }}}
(2) {{{ 35 + 5 = 2*( 15 + 5 ) }}}
(2) {{{ 40 = 2*20 }}}
(2) {{{ 40 = 40 }}}
OK