Rules of multiplying integers :
1.) just multiply the factors ,, then if the sign is like signs or Same sign , The product would be POSITIVE ... 
-4x-15= +60 or 60            4x15= 
+60 or 60
2.) If The factors Are Unlike Signs or POSITIVE x NEGATIVE & NEGATIVE x POSITIVE The Product Would Be Negative  
-4x15 = -60                      4x-15 = -60

1 5 1
In multiplying integers get first the absolute value of the two factors...(remember the signs).....when u got it...then multiply....then if the two factors has the same signs (whether its negative or positive)....the sign of their product would be positive if not the sign of the product would be negative.....

+2 x+2

-2 x+2

in multiplying integers w/ various of numbers....multiply them all first then count the positive signs.....if the positive signs are even...the product's sign will be positive if it is
odd write negative

for instance: -2 x +3 x +4=
                    2x3x4 = +24
                 -2 x -3 x +4 =
                  2x3x4+ -24