Question 102598
I. {{{x-4y=-19 }}} first find x in this one 
II. {{{-4x-5y=13}}}

then we have
{{{x = (4y) - 19}}} now put this in II. and find y
{{{-(4)4y }}}– {{{19}}} – {{{5y }}}= {{{13}}}
{{{-16y + 76 – 5y = 13}}}
{{{76 – 13 = 21y}}}
{{{21y = 63}}}
{{{y = 63/21}}}
{{{y = 3}}}

Now we can calculate x
{{{x = 4y – 19}}}
{{{x = 12 – 19}}}
{{{x = -7}}}

Check:
{{{x – 4y = - 19}}}
{{{-7 – 4*3 = -19}}}
{{{-7 -12 = -19}}}
{{{-19 = -19}}}

{{{-4x-5y=13}}}
{{{-4*(-7)-5*3=13}}}
{{{28- 15=13}}}
{{{13 =13}}}