1)Tính
a)4/5 x 9/7 - 9/5 x 3/14
=36/35 - 27/70
=72/70 - 27/70
=45/70
=9/14
b)(4,578 : 3,27 + 5,232 : 3,27) x 4,08 - 4,08
=[3,27 : (4,578+5.232)] x 4,08 - 4,08
=[3.27 : 9,81] x 4,08 - 4,08
=327/100 : 981/100 x 408/100 - 408/100
=327/100 x 100/981 x 408/100 - 408/100
=109/327 x 408/100 - 408/100
=1 x 136/100 - 408/100
=136/100 - 408/100
=-272/100
=68/25
c)3/4 - 50% + 0.25
=3/4 - 50/100 + 25/100
=75/100 - 50/100 + 25/100
=75-50+25/100
=50/100
=1/2
CHÚC BẠN HỌC TỐT !