Question 836335
Let {{{ a }}} = Ben's age now
Let {{{ b }}} = Omar's age now
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(1) {{{ a = b + 40 }}}
(2) {{{ a - 11 = 5*( b - 11 ) }}}
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(2) {{{ a - 11 = 5b - 55 }}}
(2) {{{ -a + 5b = 44 }}}
and
(1) {{{ a - b = 40 }}}
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add the equations
(2) {{{ -a + 5b = 44 }}}
(1) {{{ a - b = 40 }}}
{{{ 4b = 84 }}}
{{{ b = 21 }}}
and
(1) {{{ a = b + 40 }}}
(1) {{{ a = 21 + 40 }}}
(1) {{{ a = 61 }}}
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61 is Ben's age now
21 is Omar's age now
check:
(2) {{{ a - 11 = 5*( b - 11 ) }}}
(2) {{{ 61 - 11 = 5*( 21 - 11 ) }}}
(2) {{{ 50 = 5*10 }}}
(2) {{{ 50 = 50 }}}
OK