Question 615086
(1) {{{ -3x - 5y = 61}}}
(2) {{{ 7x - 5y = -9 }}}
Multiply both sides of (2) by {{{ -1 }}}
and add the equations
(1) {{{ -3x - 5y = 61}}}
(2) {{{ -7x + 5y = 9 }}} 
{{{ -10x = 70 }}}
Divide both sides by {{{ -10 }}}
{{{ x = -7 }}}
Plug this result back into either equation
(2) {{{ 7*(-7) - 5y = -9 }}}
(2) {{{ -49 -5y = -9 }}}
Multiply both sides by {{{ -1 }}}
(2) {{{ 49 + 5y = 9 }}}
(2) {{{ 5y = -49 + 9 }}}
(2) {{{ 5y = -40 }}}
(2) {{{ y = -8 }}}
The solution is (-7,-8)