Question 938871
Let {{{ m }}} = number of mints he buys
Let {{{ g }}} = number of gums he buys
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(1) {{{ m = 3g }}}
(2) {{{ 2m + .5g = 13 }}}
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Substitute (1) into (2)
(2) {{{ 2*(3g) + .5g = 13 }}}
(2) {{{ 6.5g = 13 }}}
(2) {{{ g = 2 }}}
and
(1) {{{ m = 3g }}}
(1) {{{ m = 3*2 }}}
(1) {{{ m = 6 }}}
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He buys 6 mints and 2 gums
check:
(2) {{{ 2m + .5g = 13 }}}
(2) {{{ 2*6 + .5*2 = 13 }}}
(2) {{{ 12 + 1 = 13 }}}
OK