Question

calcule mentalmente .

a) 5 . ( -3-1 )
b) 7 . ( 2-5 )
c) ( -8+1 ) . (-3 )
d) ( -2-3-1 ) . ( -4 )

Answer 1

a) 5 ×( -3-1 ) =5×(-4)=-20
b) 7×( 2-5 )=7×(-3)=-21
c) ( -8+1 ) × (-3 )= (-7)×(-3)=21
d) ( -2-3-1 ) × ( -4 )= (-6)×(-4)=24

Answer 2

a)5.(-3-1)
5.(-4)
-20

b)7.(2-5)
7.(-3)
-21

c)(-8+1).(-3)
-7.(-3)
21

d)(-2-3-1).(-4)
-6.(-4)
24