Question 521076
Let {{{a}}} = number of {{{ 6.58 }}} kg boxes
Let {{{b}}} = number of {{{ 10.56 }}} kg boxes
given:
(1) {{{ 6.58a + 10.56b = 2258.24 }}}
(2) {{{ b = a + 84 }}}
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substitute (2) into (1)
(1) {{{ 6.58a + 10.56*(a + 84) = 2258.24 }}}
(1) {{{ 6.58a + 10.56a + 887.04 = 2258.24 }}}
(1) {{{ 17.14a = 1371.2 }}}
(1) {{{ a = 80 }}}
and, since
(2) {{{ b = a + 84 }}}
(2) {{{ b = 80 + 84 }}}
(2) {{{ b = 164 }}}
There are 80 lighter boxes and 164 heavier boxes
check:
(1) {{{ 6.58a + 10.56b = 2258.24 }}}
(1) {{{ 6.58*80 + 10.56*164 = 2258.24 }}}
(1) {{{ 526.4 + 1731.84 = 2258.24 }}}
(1) {{{ 2258.24 = 2258.24 }}}
OK