Question 1027536
Let {{{ p }}} = Patrick's age now
Let {{{ j }}} = James's age now
Let {{{ r }}} = Rica's age now
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(1) {{{ p = 2j }}}
(2) {{{ j = r + 8 }}}
(3) {{{ p + 8 = 3*( r + 8 ) }}}
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Substitute (1) into (3)
(3) {{{ 2j + 8 = 3*( r + 8 ) }}}
(3) {{{ 2j + 8 = 3r + 24 }}}
(3) {{{ 2j - 3r = 16 }}}
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(2) {{{ j - r = 8 }}}
(2) {{{ 2j - 2r = 16 }}}
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Subtract (3) from (2)
(2) {{{ 2j - 2r = 16 }}}
(3) {{{ -2j + 3r = -16 }}}
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{{{ r = 0 }}}
and
(2) {{{ j = r + 8 }}}
(2) {{{ j =0 + 8 }}}
(2) {{{ j = 8 }}}
and
(1) {{{ p = 2j }}}
(1) {{{ p = 2*8 }}}
(1) {{{ p = 16 }}}
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James is 8 now
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check answer:
Patrick is twice as old as James
{{{ 16 = 2*8 }}}
OK
James is 8 years older than rica
{{{ 8 = 8 + 0 }}}
{{{ 8 = 8 }}}
OK
In 8 years, patrick will be 3 times as old as rica.
{{{ 16 + 8 = 3*( 0 + 8 ) }}}
{{{ 24 = 24 }}}
OK
( note that Rica being {{{ 0 }}} means just born )