4)11/8 . 6/13= 77/x
11/8 . 6/13x=77
6/13x=77:11/8
6/13x=56
x= 56:6/13
x= 364/3
5) 5x+7/8=13/12 . 4/5
5x+7/8=13/15
5x=13/15-7/8
5x= -1/120
5x= -1/120:5
x=-1/600
6)x-(-6)/15=4/27 . (-3/4)^2
x+6/15=4/27(-3/4)^2
x+2/5=4/27(-3/4)^2
x+2/5=4/27(3/4)^2
x+2/5=4/27 . 3^2/4^2
x+2/5=4/27 . 9/16
x+2/5=1/12
x=1/12-2/5
x=-19/60
7)2|x|-1/4=6/18 . 9/2
2|x|-1/4= 3/2
2|x|=3/2+1/4
2|x|=7/4
|x|=7/8
x=-7/8 hoặc x=7/8
8)-6/12 . x=9/48 . (-2/3)^3
-6/12x= 9/48 . -8/27
-6/12x= -1/18
x= -1/18:-6/12
x=-1/18 . -12/6
x=1/9
9)x-4/6=5/25 . -7/15
x-2/3=5/25 . -7/15
x-2/3=-7/75
x=-7/75+2/3
x=43/75
10)x+5/6=16/42 . -8/56
x+5/6=-8/147
x=-8/147-5/6
x=-87/98
11)x-4/5=6/20 . -7/3
x-4/5=-7/10
x=-7/10+4/5
x=1/10
12)-7/5 . 3^2=x-4/9
-7/5 . 9=x-4/9
-63/5=x-4/9
x=-63/5+4/9
x=-567/45+20/45
x=-547/45
CHÚC BẠN HỌC TỐT NHA!!!
