B.O.B.- something I didn't understand for a long time

Find x,y-interceptions:

I always had problems to find the interceptions, sometimes I could find them but normally it was just coincidence. Now I understand it, because a classmate explained me, how I can find them and what they are. He told me that when you graph a function, the x-interceptions are the 2 points, where the graph crosses the x-axis and the y-value is zero. You find the x-interceptions, when you you write them in the fallowing term: (.....)(....)
When you got so far, you have to take the opposite of what is done with the number in the brackets (change sign!).
For example: (x-3)(x+4), Then the x-interceptions would be 3 for x and zero for y; and -4 for x and zero for y. Also often written as: (3,0) (-4,0)
To find the y-interception is easier, because there is always just one, because the graph crosses the y-axis only once. To find the y-interception you don't have to write it in this (....)(....) -form, or when it is already in this form, you have to distribute it to find the y-interception.
For example: x^2-3x+5, here the y-interception is five, because here the sign doesn't change.

Instructions to find x-intercepts:
1) put the equation in the fallowing form: (....)(....)
2) change the signs of the numbers in the brackets and you get 2 numbers, those are your x-interceps with y=0

Instructions to find the y-intercept:
1) put the equation in the fallowing form: x^2+3x-2 (just an example)
2) the y-interception is -2, always the number without an x and here: don't change the sign!