@ Đạt em
Xem cách giải sau :
↓↓↓↓↓↓↓↓↓
a) 0,125 x 2 x 8 x 4 x 0,5 x 0,25
= ( 0,125 x 8 ) x ( 0,25 x 4 ) x ( 0,5 x 2 )
= 1 x 1 x 1
= 1
b) `3030/1717` x `343434/151515` x `2121/1818`
= `30/17` x `34/15` x `7/6`
= ( `30/17` x `34/15` ) x `7/6`
= `1020/255` x `7/6`
= 4 x `7/6`
= `28/6`
= `14/3`