Question 697623
Let {{{ s }}} = the share for 1 son
Let {{{ d }}} = the share for the daughter
Let {{{ w }}} = the share for the widow
given:
(1) {{{ 2s + d + w = 525000 }}}
(2) {{{ s = 2d }}}
(3) {{{ w = 8s }}}
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(2) {{{ d = s/2 }}}
Substitute this into (1) 
(1) {{{ 2s + s/2 + w = 525000 }}}
and, also, substitute (3) into (1)
(1) {{{ 2s + s/2 + 8s = 525000 }}}
(1) {{{ 4s + s + 16s = 1050000 }}}
(1) {{{ 21s = 1050000 }}}
(1) {{{ s = 50000 }}}
and
{{{ w = 8s }}}
{{{ w = 400000 }}}
The widow's share is $400,000
check:
(2) {{{ d = s/2 }}}
(2) {{{ d = 25000 }}}
and
(1) {{{ 2s + d + w = 525000 }}}
(1) {{{ 2*50000 + 25000 + 400000 = 525000 }}}
(1) {{{ 100000 + 425000 = 525000 }}}
(1) {{{ 525000 = 525000 }}}
OK