Question 1117799
Let {{{ a }}} = Gina's mother's age now
Let {{{ b }}} = Gina's age now
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(1) {{{ a = 5b }}}
(2) {{{ a + 18 = 2*( b + 18 ) }}}
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Plug (1) into (2)
(2) {{{ 5b + 18 = 2*( b + 18 ) }}}
(2) {{{ 5b + 18 = 2b + 36 }}}
(2) {{{ 3b = 18 }}}
(2) {{{ b = 6 }}}
and
(1) {{{ a = 5b }}}
(1) {{{ a = 5*6 }}}
(1) {{{ a = 30 }}}
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Gina's mother is 30
Gina is 6
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check:
(2) {{{ a + 18 = 2*( b + 18 ) }}}
(2) {{{ 30 + 18 = 2*( 6 + 18 ) }}}
(2) {{{ 48 = 2*24 }}}
(2) {{{ 48 = 48 }}}
OK