Question 831018
Let {{{ e }}} = Esther's age now
Let {{{ m }}} = her mother's age now
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(1) {{{ e = m - 18 }}}
(2) {{{ ( e-2 ) + ( m-2 ) = 70 }}}
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(1) {{{ -e + m = 18 }}}
and
(2) {{{ e + m - 4 = 70 }}}
(2) {{{ e + m = 74 }}}
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Add (1) and (2)
(1) {{{ -e + m = 18 }}}
(2) {{{ e + m = 74 }}}
{{{ 2m = 92 }}}
{{{ m = 46 }}}
and, since
(1) {{{ e = m - 18 }}}
(1) {{{ e = 46 - 18 }}}
(1) {{{ e = 28 }}}
Esther is 28 and her mother is 46 
check:
(2) {{{ ( e-2 ) + ( m-2 ) = 70 }}}
(2) {{{ ( 28-2 ) + ( 46-2 ) = 70 }}}
(2) {{{ 26 + 44 = 70 }}}
(2) {{{ 70 = 70 }}}
OK