Question 415976
 x+3y=-3

first rewrite the function in slope intercept form, y = mx + b


{{{ x+3y=-3 }}}


{{{ x+3y - x= -x -3 }}}

{{{  3y  = -x -3 }}}

{{{  3y/3  = -x/3 -3/3 }}}

{{{   y  = -x/3 - 1 }}}


here the y-intercept is -1
That is,  (0,-1)  remember, x coordinate will be always 0 for the y-intercept.