Question 644533
Let {{{ a }}} = pounds of apple slices used
Let {{{ b }}} = pounds of banana slices used
given:
(1) {{{ 1.8a + 2.1b = 5*1.92 }}}
(2) {{{ a + b = 5 }}}
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(2) {{{ b = 5 - a }}}
Substitute (2) into (1)
(1) {{{ 1.8a + 2.1*( 5 - a ) = 5*1.92 }}}
(1) {{{ 1.8a + 10.5 - 2.1a = 9.6 }}}
(1) {{{ 1.8a - 2.1a = 9.6 - 10.5 }}}
(1) {{{ -.3a = -.9 }}}
(1) {{{ a = 3 }}}
3 pounds of apple slices were used
check:
(2) {{{ a + b = 5 }}}
(2) {{{ b = 2 }}}
and
(1) {{{ 1.8*3 + 2.1*2 = 5*1.92 }}}
(1) {{{ 5.4 + 4.2 = 9.6 }}}
(1) {{{ 9.6 = 9.6 }}}
OK