1) 594:(8х-55)=18
(8x - 55) = 594 : 18;
(8x - 55) = 33;
8x = 33 + 55;
8x = 88;
x = 11;
2) 735:(6x+17) = 21;
6x + 17 = 735:21;
6x + 17 = 35;
6x = 35 - 17;
6x = 18;
x = 3;