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Multiplication |
Multiplication:
by zero:
a x 0 = 0 , -b x 0 = 0
132 x 0 = 0
-20 x 0 = 0
by -1:
a x -1 = -a , -b x -1 = b
242 x -1 = -242
-132 x -1 = 132
Positive and negative multiplication:
-a x +b = -(ab)=> (neg x pos = neg)
-a x -b = +(ab)=>(neg x neg = pos)
2 x - 3 = -6
-3 x -4 = 12
-2 x - 3 x -2 = (-2 x -3) x -2 = 6 x -2 = - 12
-2 x - 3 x - 2 x - 1 = (-2 x -3) x -2 x -1 = 6 x -2 x -1 =(6 x -2) x -
1 =-12 x - 1 = 12
Cancellation Property:
if ac = bc, then a = b (c not equal to 0)
12a = 12b, then a = b
13a = 26 = 13 x 2, so a = 2