1) 0,6x + 100 = 0,9x + 1
100 - 1 = 0,9x - 0,6x
99 = 0,3x
x = 99/0,3 = 990/3 = 330
2) -9/14*x + 18 = -2/3*x + 17
2/3*x - 9/14*x = 17 - 18
(28x - 27x)/42 = -1
x/42 = -1
x = -1/42
3) -8/15*x - 11 = 4/9*x + 11
-11 - 11 = 4/9*x + 8/15*x
-22 = (4*5x + 8*3x)/45
20x + 24x = -22*45
44x = -22*45
2x = -45
x = -45/2