a 15,46+22,91+4,54+77,09 b (16/30+9/10)+21/10
=(15,46+4,54)+(22,91+77,09) =16/30+(9/10+21/10)
=20+100 =16/30+30
=120 =53/15
nhớ k cho mình nhé
a, 15,46 + 22,91 + 4,54 + 77,09
= ( 15,46 + 4,54 ) + ( 22,91 + 77,09 )
= 20 + 100
= 120
b, ( 16/30 + 9/10 ) + 21/10
= 16/30 + 9/10 + 21/10
= 16/30 + 3
= 16/30 + 30/30
= 46/30