Please expand (y+2)(y-3).

We will use the FOIL method. Here FOIL stands for: First, Outside, Inside, Last.
This means we start by multiplying the first terms in each bracket together to get y² .
Then we multiply the outside terms together, these are the furthest left and furthest right terms, so y and -3 giving -3y. (Don't forget the minus sign!)
Next we multiply the inside terms (the middle two terms) which are 2 and y giving 2y.
Finally we multiply the last terms in each bracket together which gives 2 x -3= -6.
Now add them together and write it out: (y+2)(y-3)=y²+2y-3y-6
Now collect like terms to give y²-y-6.