1. 26-5m=2-9m    2. 9z+11=13z-1    3. 12a+31=23a-2   4. 2(x-2)-1=5(x-2)-7   5.

1.
26-5m=2-9m
9m-5m=2-26
4m=-24
m=-24/4
m=6
2.
9z+11=13z-1
9z-13z=-11-1
-4z=-12
z=12/4
z=3
3.
12a+31=23a-2
12a-23a=-31-2
-11a=-33
a=33/11
a=3
4.
2(x-2)-1=5(x-2)-7
2x-4-1=5x-10-7
2x-5=5x-17
2x-5x=5-17
-3x=-12
x=12/3
x=4
5.
-y+20=-y
какое то неточное
6.
4(2y-6)=4y-4
8y-24=4y-4
8y-4y=24-4
4y=20
y=20/4
y=5
7.
-9n+3=3(8n+45)
-9n+3=24n+135
-9n-24n=-3+135
-33n=132
n=-132/33
n=-4
8.
20+5m=44+m
-m+5m=44-20
4m=24
m=24/4
m=6
9.
27-4k=3-8k
8k-4k=3-27
4k=-24
k=-24/4
k=6
10.
5b+11=7b-3
5b-7b=-11-3
-2b=-12
b=12/2
b=6
11.
8a+11=4a-1
8a-4a=-11-1
4a=-12
a=-12/4
a=3