Question 969444
{{{4a=-7b+2}}}
{{{a=-(7/4)b+2}}}


substitution:
{{{5(2-(7/4)b)+b=-13}}}


{{{10-35b/4+b=-13}}}
{{{-35b/4+b=-23}}}
{{{35b/4-b=23}}}
{{{35b-4b=92}}}
{{{31b=92}}}
{{{highlight(b=92/31)}}}


Now find value for a.
{{{a=2-(7/4)b}}}
{{{a=2-(7/4)(92/31)}}}
{{{a=2-(7*92)/(4*31)}}}
{{{a=(2(4*31)-7*92)/(4*31)}}}
{{{a=-396/(4*31)}}}
{{{highlight(a=-99/31)}}}