Question 1124133
Let {{{ a }}} = Kofi’s age now
Let {{{ b }}} = Kojo’s age now
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(1) {{{ a = 4b }}}
(2) {{{ a + 10 = 2*( b + 10 ) }}}
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By substitution:
(2) {{{ 4b + 10= 2*( b + 10 ) }}}
(2) {{{ 4b + 10 = 2b + 20 }}}
(2) {{{ 2b = 10 }}}
(2) {{{ b = 5 }}}
And
(1) {{{ a= 4b }}}
(1) {{{ a = 4*5 }}}
(1) {{{ a = 20 }}}
And
{{{ a + 10 = 30 }}}
{{{ b + 10 = 15 }}}
Kefir will be 20
Mojo will be 15