Question 575628
Let {{{ s }}} = number of stools
Let {{{ c }}} = number of chairs
given:
(1) {{{ s + c = 30 }}}
(2) {{{ 3s + 4c = 103 }}}
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Multiply both sides of (1) by {{{ 3 }}},
and subtract (1) from (2)
(2) {{{ 3s + 4c = 103 }}}
(1) {{{ -3s - 3c = -90 }}}
{{{ c = 13 }}}
and
(1) {{{ s + c = 30 }}}
(1) {{{ s + 13 = 30 }}}
(1) {{{ s = 30 - 13 }}}
(1) {{{ s = 17 }}}
The carpenter made 17 stools and 13 chairs
check:
(2) {{{ 3s + 4c = 103 }}}
(2) {{{ 3*17 + 4*13 = 103 }}}
(2) {{{ 51 + 52 = 103 }}}
(2) {{{ 103 = 103 }}}
OK