Question 597336
Let {{{ f }}} = Father's age now
Let {{{ s }}} = Son's age now
given:
(1) {{{ f + 10 = 2*( s + 10 ) }}}
(2) {{{ f - 10 = 6*( s - 10 ) }}}
------------------------
(1) {{{ f + 10 = 2s + 20 }}}
(1) {{{ f - 2s = 10 }}}
and
(2) {{{ f - 10 = 6s - 60 }}}
(2) {{{ f - 6s = -50 }}}
Subtract (2) from (1)
(1) {{{ f - 2s = 10 }}}
(2) {{{ -f + 6s = 50 }}}
{{{ 4s = 60 }}}
{{{ s = 15 }}}
and
(1) {{{ f - 2s = 10 }}}
(1) {{{ f - 2*15 = 10 }}}
(1) {{{ f - 30 = 10 }}}
(1) {{{ f = 40 }}}
The father is 40
The Son is 15
check:
(1) {{{ 40 + 10 = 2*( 15 + 10 ) }}}
(1) {{{ 50 = 2*25 }}}
(1) {{{ 50 = 50 }}}
(2) {{{ 40 - 10 = 6*( 15 - 10 ) }}}
(2) {{{ 30 = 6*5 }}}
(2) {{{ 30 = 30 }}}
OK