Question 1006744
Let {{{ j }}} = Julia's age now
Let {{{ a }}} = Allison's age now
{{{ j + 2 }}} = Julia's age in 2 years
{{{ a + 2 }}} = Allison's age in 2 years
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(1) {{{ j = a - 20 }}}
(2) {{{ a + 2 = 2*( j + 2 ) }}}
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(1) {{{ a - j = 20 }}}
and
(2) {{{ a + 2 = 2j + 4 }}}
(2) {{{ a - 2j = 2 }}}
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Subtract (2) from (1)
(1) {{{ a - j = 20 }}}
(2) {{{ -a + 2j = -2 }}}
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{{{ j = 18 }}}
and
(1) {{{ a - j = 20 }}}
(1) {{{ a - 18 = 20 }}}
(1) {{{ a = 38 }}}
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Allison is 38
Julia is 18 
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check:
(2) {{{ a + 2 = 2*( j + 2 ) }}}
(2) {{{38 + 2 = 2*( 18 + 2 ) }}}
(2) {{{ 40 = 2*20 }}}
(2) {{{ 40 = 40 }}}
OK