Question 561199
(1) {{{ 7x - 2 = 2y }}} 
(2) {{{ 3x = 2y - 1 }}}
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(2) {{{ 2y = 3x + 1 }}}
Substitute this value of {{{ 2y }}} into (1)
(1) {{{ 7x - 2 = 3x + 1 }}}
Subtract {{{ 3x }}} from both sides
(1) {{{ 4x = 3 }}}
(1) {{{ x = 3/4 }}}
and, since
(2) {{{ 2y = 3x + 1 }}}
(2) {{{ 2y = 3*(3/4) + 1 }}}
Multiply both sides by {{{ 4 }}}
(2) {{{ 8y = 9 + 4 }}}
(2) {{{ 8y = 13 }}}
(2) {{{ y = 13/8 }}}
The solution is (3/4, 13/8)
check answers:
(1) {{{ 7x - 2 = 2y }}} 
(1) {{{ 7*(3/4) - 2 = 2*(13/8) }}}  
(1) {{{ 21/4 - 8/4 = 13/4 }}} ( I made 2 = 8/4 )
(1) {{{ 21/4 = 8/4 + 13/4 }}}
(1) {{{ 21/4 = 21/4 }}}
OK 
(2) {{{ 3x = 2y - 1 }}}
(2) {{{ 3*(3/4) = 2*(13/8) - 1 }}}
(2) {{{ 9/4 = 13/4 - 4/4 }}}
(2) {{{ 9/4 = 9/4 }}}
OK