Bài 2: Tính bằng 2 cách:
a) ( 2/3 x 4/5 ) x 5/6=……………………………………………….
=………………………………………………
=…………………………………………….
b) ( 2/3 x 4/5 ) x 5/6 =…………………………………………..
=…………………………………………..
= ………………………………………….
c) ( 1/2 x 1/3 ) x 1/5 =…………………………………………..
=………………………………………….
=………………………………………….
d) ( 1/2 x1/3 ) x 1/5 =…………………………………………..
=…………………………………………
=…………………………………………..
Gấp
a) ( 2/3 x 4/5 ) x 5/6=
Cách 1: a) ( 2/3 x 4/5 ) x 5/6= 8/15 x 5/6 = 4/9
Cách 2: a) ( 2/3 x 4/5 ) x 5/6= 2/3 x 4/5 x 5/6 = 2/3 x(4/5 x 5/6)=2/3 x 2/3 = 4/9
c) ( 1/2 x 1/3 ) x 1/5
Cách 1: c) ( 1/2 x 1/3 ) x 1/5 = 1/6 x 1/5 = 1/30
Cách 2: c) ( 1/2 x 1/3 ) x 1/5 = 1/2 x 1/3 x 1/5 = (1/2 x 1/5) x 1/3 = 1/10 x 1/3 = 1/30
a, (2/3 x 4/5)x5/6
= 8/15 x 5/6
= 40/90=4/9
Cách 2
(2/3 x 4/5)x5/6
= 2/3 x (4/5×5/6)
= 2/3 x 20/30
= 40/90=4/9
b,Giống a ko làm
c, (1/2 x 1/3) x 1/5
=1/6 x 1/5
= 1/30
Cách 2
(1/2 x 1/3) x 1/5
= 1/2 x (1/3 x 1/5)
= 1/2 x 1/15
= 1/30
d,giống c nhé