Câu 1 :
a) 25/-5 . -18/-27 . 24/48 . 7
= -5 . 2/3 . 1/2 . 7
= ( -5.7) (2/3 . 1/2)
= -35 . 1/2
= -35/2
b) 2/3 : (-7)/5 + 2/3.2/5
= 2/3.( -7/5 + 2/5)
= 2/3 . 1
= 2/3
Câu 2:
a) 3/2x - 1/2 = 3/4
3/2x = 3/4 + 1/2
3/2x = 5/4
x = 5/4 : 3/2
x = 5/6
b) -2/5x + 2 = -6/7
-2/5x = -6/7 - 2
-2/5x = -20/7
x = -20/7 : (-2)/5
x = 50/7
Xin hay nhất nha bạn :)