tính bằng 2 cách
a) 24 x ( 3 + 5 ) b) 12 x 3 + 12 x 5
36 x ( 9 + 1 ) 25 x 6 + 25 x 4
c)28 x ( 7 – 2 ) d) 79 x 5 – 79 x 3
135 x ( 10 – 1 ) 564 x 10 – 564 x 8
Đáp án:
c1 : 24 x (3 + 5 ) = 24 x 8
= 192
c2: 24 x ( 3 + 5 )= 24 x 3 + 24 x 5
= 72 + 120
=192
36 x ( 9+1)=36 x 10
= 360
36 x ( 9+1) = 36 x 9 + 36 x 1
= 324 + 36
= 360
c1 : 24 x (3 + 5 ) = 24 x 8
= 192
c2: 24 x ( 3 + 5 )= 24 x 3 + 24 x 5
= 72 + 120
=192
c1: 36 x ( 9+1)=36 x 10
= 360
c2: 36 x ( 9+1) = 36 x 9 + 36 x 1
= 324 + 36
= 360