Question

Tính: 

a) 21.(-3);

b) (-16).5;

c) 12.20;

d) (-21).(-6).

Answer 1

a) 21 . (- 3) = - (21 . 3) = - 63

b) (- 16 ) . 5 = - (16 . 5) = - 80

c) 12 . 20 = 240 d) (- 21) . (- 6) = 126

Answer 2

a) 21 . (- 3) = - (21 . 3) = - 63

b) (- 16 ) . 5 = - (16 . 5) = - 80

c) 12 . 20 = 240

d) (- 21) . (- 6) = 126

Answer 3

a) 21 . (-3) = - (21.3) = - 63

b) (-16).5 = - (16.5)= - 80

c) 12. 20 = 240

d) (-21).(-6)=21.6 = 126

Answer 4

a) \(21\cdot\left(-3\right)=-\left(21\cdot3\right)=-63\)

b) \(\left(-16\right)\cdot5=-\left(16\cdot5\right)=-80\)

c) \(12\cdot20=24\cdot10=240\)

d) \(\left(-21\right)\cdot\left(-6\right)=21\cdot6=126\)