we have that
x+2y=4------------ > y=(4-x)/2
the x-intercepts is the value of X for y=0
0=(4-x)/2------------ > x=4--------------------> (4,0)
the y-intercepts is the value of y for x=0
y=(4-0)/2------------- > y=2-------------------> (0,2)
see the attached figure