finding the x and y-intercept of

x-y-3=0

Think about it this way. What is the equation of the x axis; (x=0 ; y=-inf to + inf)
What is the equation of the y axis (y=0, x=-inf to + inf)

Solve the two sets of equations.
x-y-3=0; x=0


and x-y-3=0; y=0