Đáp án:
Giải thích các bước giải:
Bài 1
A,(-5)-1/6 =(-5/1)-1/6=(-30/6)-1/6=-31/6
B,2/3+1/5.10/7=2/3+2/7=14/21+6/21=20/21
C,5/8.7/13+5/8.9/13-5/8.3/13
=5/8.(7/13+9/13-3/13)
=5/8.(16/13-3/13)
=5/8.13/13
=5/8.1
=5/8
Bài 2
A,x+5=2
x =2-5
x =-3
B,x-1/2=-3/4
x =-3/4+1/2
x =-3/4+2/4
x =-1/4