21-6x=27-8x
21 - 27 = - 8x + 6x
- 6 = - 2x
-6/-2 = x
3 =x
11x+5x-1=65x-36
11x +5x - 65x = - 36 + 1
- 49x = - 35
x = -35/-49
x = 35/49
x = 5/7
8x-4+3x=7+x+14
8x + 3x -x = 7 +14 + 4
10x = 25
x = 25/10
x = 2,5
8x+9-12=4x-13-5x
8x -4x + 5x = - 13 + 12 - 9
9x = -1
x = - 1/9
5y+6y-81=7y+102+65y
5y + 6y - 7y - 65y = 102 +81
-61y = 183/-61
y = - 3
espero que te sirva, salu2!!!
