bài 1:
a)tự ghi đề
=-5/4+1/4+1/2
=-1+1/2
=-1/2
b)1/2+1/2.(-80).1/100-1/10
=1/2+1/2.-4/5-1/10
=1/2+5/10.-8/10-1/10
=1/2+2/5-1/10
=5/10+4/10-1/10
=4/5
c)
=2/15.2/5+2/15.4/5+2/15.-1/5
=2/15.(2/5+4/5+-1/5)
=2/15.1
2/15
bài 2:
a)x=45:1/100
x=45.100
x=4500
b)9/4-9/4.(5/4-y)=27/16
9/4.(5/4-y)=27/16+9/4
9/4.(5/4-y)=63/16
5/4-y=63/16:9/4
5/4-y=7/4
y=5/4-7/4
x=-1/2
c này mik chưa nghĩ ra nhé thông cảm
xin ctlhn luôn ạ
