I.TRẮC NGHIÊM
1-C 2-B 3-A 4-C
5. a,S b,Đ c,Đ d,S
II.TỰ LUẬN
Bài 1:
a,-6/x=(-8)/12=>x.(-8)=(-6).12
x.(-8)=-72
x =-72:(-8)
x =9
b,x/-7=14/49=>x.49=14.(-7)
x.49=-98
x =-98:49
x =-2
c,x-2/15=9/5=>(x-2).5=15.9
(x-2).5=135
x-2 =135:5
x-2 =27
x =27+2
x =29
d,14/8=x-1/4=>(x-1).8=14.4
(x-1).8=56
x-1 =56:8
x-1 =7
x =7+1
x =8