Question

1995+1995×1996-1997×1994. b)1997×109-199700-1997×7-1997(utilizand factorul comun)

Answer 1

1 995 + 1995 × 1996 - 1997 × 1994 =  1 997

= 1 995 × ( 1 + 1 996 ) - 1 997 × 1 994 =

= 1 995 × 1997 - 1 997 × 1 994 =

= 1 997 × ( 1 995 - 1 994 ) =

= 1 997 × 1 =

= 1 997

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b)  

1 997 × 109 - 199700 - 1997 × 7 - 1997 = 1 997

= 1 997 × ( 109 - 100 - 7 - 1 ) =

= 1 997 × ( 9 - 7 - 1 ) =

= 1 997 × 1 =

= 1 997