1.
a.( 8/5 + 5/6 ) : 7/6
= 73/30 : 7/6
= 73/35
b.2/5 + 1/2 + 7/10
= 7/5 + 7/10
= 21/10
c.1/2 x 1/3 + 3/10
= 1/6 + 3/10
=7/15
d.3/5 + 1/12 + 8/15
= 41/60 + 8/15
= 73/60
đ. = 17/9
e. = 35/24
g. = 7/40
h. = 4/5
2.
a. 13/7 + 5/6 + 2/7 + 7/6
= ( 13/7 + 2/7 ) + ( 5/6 + 7/6 )
= 15/7 + 12/6
= 29/7
b. 3/5 x 17/21 + 17/21 x 2/5
= 17/21 x ( 3/5 + 2/5 )
mik lm đến đây thôi, bận òi
