Question 967583
(1) {{{ b/ g = 4/3 }}}
(2) {{{ b - 3 = g + 4 }}}
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(1) {{{ 3b = 4g }}}
(1) {{{ b = (4/3)*g }}}
Substitute this result into (2)
(2) {{{ (4/3)*g - 3 = g + 4 }}}
(2) {{{ 4g - 9 = 3g + 12 }}}
(2) {{{ g = 21 }}}
and
(1) {{{ b = (4/3)*g }}}
(1) {{{ b = (4/3)*21 }}}
(1) {{{ b = 28 }}}
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{{{ 21 + 28 = 49 }}}
49 students signed up
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check:
(1) {{{ b/ g = 4/3 }}}
(1) {{{ 28/ 21 = 4/3 }}}
(1) {{{ 4/3 = 4/3 }}}
and
(2) {{{ b - 3 = g + 4 }}}
(2) {{{ 28 - 3 = 21 + 4 }}}
(2) {{{ 25 = 25 }}}
OK