Question 692984
Let {{{ a }}} = Shirley's age now
Let {{{ b }}} = Kim's age now
{{{ a - 4 }}} = Shirley's age 4 yrs ago
{{{ a + 4 }}} = Shirley's age 4 years from now
{{{ b - 4 }}} = Kim's age 4 yrs ago
{{{ b + 4 }}} = Kim's age 4 yrs from now
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given:
(1) {{{ a - 4 = 4*( b - 4 ) + 2 }}}
(2) {{{ a + 4 = 3*( b + 4 ) }}}
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(1) {{{ a - 4 = 4b - 16 + 2 }}}10
(1) {{{ a - 4 = 4b - 14 }}}
(1) {{{ a - 4b = - 10 }}}
and
(2) {{{ a + 4 = 3b + 12 }}}
(2) {{{ a - 3b = 8 }}}
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Subtract (1) from (2)
(2) {{{ a - 3b = 8 }}}
(1) {{{ -a + 4b = 10 }}}
{{{ b = 18 }}}
and
(2) {{{ a - 3b = 8 }}}
(2) {{{ a = 3b + 8 }}}
(2) {{{ a = 3*18 + 8 }}}
(2) {{{ a = 54 + 8 }}}
(2) {{{ a = 62 }}}
Shirley is 62
Kim is 18
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check:
(1) {{{ a - 4 = 4*( b - 4 ) + 2 }}}
(1) {{{ 62 - 4 = 4*( 18 - 4 ) + 2 }}}
(1) {{{ 58 = 4*14 + 2 }}}
(1) {{{ 58 = 58 }}}
OK
and
(2) {{{ a + 4 = 3*( b + 4 ) }}}
(2) {{{ 62 + 4 = 3*( 18 + 4 ) }}}
(2) {{{ 66 = 3*22 }}}
(2) {{{ 66 = 66 }}}
OK