Question 571517
{{{ c }}} = Cecile's age now
{{{ d }}} = Daisy's age now
{{{ c - 5 }}} = Cecile's age 5 yrs ago
{{{ d - 5 }}} = Daisy's age 5 yrs ago
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given:
(1) {{{ c = 4d }}}
(2) {{{ ( c - 5 ) + ( d - 5 ) = 45 }}}
Substitute (1) into (2)
(2) {{{ 4d - 5 + d - 5 = 45 }}}
(2) {{{ 5d - 10 = 45 }}}
(2) {{{ 5d = 55 }}}
(2) {{{ d = 11 }}}
and, since
(1) {{{ c = 4d }}}
(1) {{{ c = 4*11 }}}
(1) {{{ c = 44 }}}
Cecile is 44 and Daisy is 11
check:
(2) {{{ ( 44 - 5 ) + ( 11 - 5 ) = 45 }}}
(2) {{{ 39 + 6 = 45 }}}
(2) {{{ 45 = 45 }}}
OK