Question 896295
Let {{{ t }}} = Tom's age now
Let {{{ d }}} = his daughter's age now
{{{ t + 5 }}} = Tom's age in {{{ 5 }}} years
{{{ d + 5 }}} = his daughter's age in {{{ 5 }}} years
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(1) {{{ t = 4d }}}
(2) {{{ t + 5 = 3*( d + 5 ) }}}
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(2) {{{ t + 5 = 3d + 15 }}}
(2) {{{ t - 3d = 10 }}}
Substitute (1) into (2)
(2) {{{ 4d - 3d = 10 }}}
(2) {{{ d = 10 }}}
and
(1) {{{ t = 4d }}}
(1) {{{ t = 4*10 }}}
(1) {{{ t = 40 }}}
Tom is 40  and
his daughter is 10
check:
(2) {{{ t + 5 = 3*( d + 5 ) }}}
(2) {{{ 40 + 5 = 3*( 10 + 5 ) }}}
(2) {{{ 45 = 3*15 }}}
(2) {{{ 45 = 45 }}}
OK