Question 6161
Must be an arithmetic error!
Look for the simplest way to eliminate one of the variables. Since both equations contain 3x, subtracting one from the other will eliminate x.
{{{3x+4y=19}}}
{{{3x+6y=33}}}
{{{-3x-4y=-19}}} [subtract the first from the second]
{{{2y=14}}}
{{{y=7}}}
{{{3x+28=19}}}  [substitute 7 for y]
{{{3x=-9}}}
{{{x=-3}}}