Question 475986
{{{system(5u-v=0, 3u+3v=-18)}}}
Myltiply the first equation by 3
{{{system(15u-3v=0, 3u+3v=-18)}}} 
Add the first equation to the second
{{{18u=-18}}} divide by 18
{{{u=-1}}}
Substitute {{{u=-1}}} into the first equation
{{{5*(-1)-v=0}}}
{{{-5-v=0}}}
{{{-v=5}}}
{{{v=-5}}}
So
{{{system(u=-1, v=-5)}}} the solution of the system
Answer: (-1, -5)