-57.11
= -57.(10 + 1)
= -57.10 + (-57).1
= -570 + (-57)
= -627
75.(-21)
= 75.(-22 + 1)
= 75.(-22) + 75.1
= -1650 + 75
= -1575
-57. 11 = -57. (10 + 1) = -570 - 57 = -627
75. (-21) = 75. (-10 - 10 - 1) = -750 - 750 -75= -16...
-57 . 11
= -57 . ( 10 + 1 )
= -57 . 10 + ( -57 ) . 1
= -570 + ( -57 )
= -627
75 . ( -21 )
= 75 . ( -22 + 1 )
= 75 . ( -22 ) + 75 . 1
= -1650 + 75
= -1575
:)