Question 555415
Let {{{ g }}} = George's age now
Let {{{ j }}} = Janet's age now
given:
(1) {{{ g = j + 3 }}}
(2) {{{ j + 7 = (6/7)*( g + 7 ) }}}
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(1) {{{ j = g - 3 }}}
Substitute (1) into (2)
(2) {{{ g - 3 + 7 = (6/7)*( g + 7 ) }}}
(2) {{{ 7*( g + 4 ) = 6*( g + 7 ) }}}
(2) {{{ 7g + 28 = 6g + 42 }}}
(2) {{{ g = 42 - 28 }}}
(2) {{{ g = 14 }}}
and, since
(1) {{{ j = g - 3 }}}
(1) {{{ j = 14 - 3 }}}
(1) {{{ j = 11 }}}
George is 14
check answer
(2) {{{ j + 7 = (6/7)*( g + 7 ) }}}
(2) {{{ 11 + 7 = (6/7)*( 14 + 7 ) }}}
(2) {{{ 18 = (6/7)*21 }}}
(2) {{{ 18*7 = 6*21 }}}
(2) {{{ 126 = 126 }}}
OK