Câu 1)
a)1-1/2+1/3
=1/2+1/3
=5/6
b)2/5+3/5: 9/10
=2/5+2/3
=16/15
c)7/11 . 3/4 +7/11 . 1/4 +4/11
=7/11 .( 3/4+1/4)+4/11
=7/11 . 1 +4/11
=7/11+4/11
=1
d)(3/4+0,5+25%). 2 phẩy 2/3
=(3/4+1/2+1/4). 8/3
=3/2. 8/3
=4
Câu 2)
a)x+1/2=2
x=2-1/2
x=3/2
b)75%x-1/2=-1 phẩy 1/4
3/4x -1/2 =-5/4
3/4x =-5/4+1/2
3/4x =-3/4
x =-3/4: 3/4
x = -1
c)[x-2/5]+7/10=3
x-2/5 =3-7/10
x-2/5 =23/10
x =23/10+2/5
x =27/10
*chúc bạn học tốt *
