Question 1024364
Let {{{ x }}} = cups of milk needed
Let {{{ y }}} = cups of cream needed
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(1) {{{ x + y = 26 }}}
(2) {{{ ( .03x + .27y ) / 26 = .11 }}}
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(2) {{{ .03x + .27y = 2.86 }}}
(2) {{{ 3x + 27y = 286 }}}
Multiply both sides of (1) by {{{ 3 }}}
and subtract (1) from (2)
(2) {{{ 3x + 27y = 286 }}}
(1) {{{ -3x - 3y = - 78 }}}
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{{{ 24y = 208 }}}
{{{ y = 8.667 }}}
and
(1) {{{ x + y = 26 }}}
(1) {{{ x = 17.333 }}}
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17 and 1/3 cups of milk are needed
8 and 2/3 cups of cream are needed
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check:
(2) {{{ ( .03x + .27y ) / 26 = .11 }}}
(2) {{{ ( .03*17.333 + .27*8.667 ) / 26 = .11 }}}
(2) {{{ ( .52 + 2.34 ) / 26 = .11 }}}
(2) {{{ 2.86 / 26 = .11 }}}
(2) {{{ 2.86 = 2.86 }}}
OK