Question 1087059
Let {{{ m }}} = Elsa's mother's age now
Let {{{ e }}} = Elsa's age now
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(1) {{{ m = 5e }}}
(2) {{{ e + 5 = (1/3)*( m + 5 ) }}}
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(2) {{{ 3*( e + 5 ) = m + 5 }}}
(2) {{{ 3e + 15 = m + 5 }}}
(2) {{{ m - 3e = 10 }}}
Substitute (1) into (2)
(2) {{{ 5e - 3e = 10 }}}
(2) {{{ 2e = 10 }}}
(2) {{{ e = 5 }}}
and
(1) {{{ m = 5e }}}
(1) {{{ m = 5*5 }}}
(1) {{{ m = 25 }}}
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Elsa is 5 and her mother is 25
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check:
(2) {{{ e + 5 = (1/3)*( m + 5 ) }}}
(2) {{{ 5 + 5 = (1/3)*( 25 + 5 ) }}}
(2) {{{ 10 = (1/3)*30 }}}
(2) {{{ 10 = 10 }}}
OK