the standard equation of a line is ax+by=c where a should not be negative
so
[tex] \frac{-2}{5} x -y=-4
[/tex]
multiply by -1 to make the x coefficient positive
[tex] \frac{2}{5} x+y=4 [/tex]
so we multiply by 5 to make them integers
[tex]2x+5y=20[/tex]
A=2,B=5,C=20