Question 334104
(1) {{{10x - 4y = -20}}}
(2) {{{10x - 5y = 35}}}
Multiply both sides of (2) by {{{-1}}} and
add to (1)
(1) {{{10x - 4y = -20}}}
(2) {{{-10x + 5y = -35}}}
{{{y = -55}}}
Now substitute this value for {{{y}}} in either 
(1) or (2) to find {{{x}}}
(1) {{{10x - 4y = -20}}}
(1) {{{10x - 4*(-55) = -20}}}
{{{10x + 220 = -20}}}
{{{10x = -240}}}
{{{x = -24}}}