Question 758571
Let {{{ j }}} = Jack's age now
Let {{{ s }}} = Sarah's age now
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given:
(1) {{{ j = s + 5 }}}
(2) {{{ j + 3 = 2*( s + 3 ) }}}
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By substitution:
(2) {{{ s + 5 + 3 = 2*( s + 3 ) }}}
(2) {{{ s + 8 = 2s + 6 ) }}}
(2) {{{ s = 8 - 6 }}}
(2) {{{ s = 2 }}}
and
(1) {{{ j = s + 5 }}}
(1) {{{ j = 2 + 5 }}}
(1) {{{ j = 7 }}}
jack is 7 and Sarah is 2
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check:
(2) {{{ j + 3 = 2*( s + 3 ) }}}
(2) {{{ 7 + 3 = 2*( 2 + 3 ) }}}
(2) {{{ 10 = 2*5 }}}
(2) {{{ 10 = 10 }}}
OK