1) 6 • (x – 1,82) = 25,2;
x – 1,82 = 25,2 : 6;
x – 1,82 = 4,2;
x = 4,2 + 1,82;
x = 6,02;
2) 45 : (2,8 + x) = 12;
2,8 + x = 45 : 12;
2,8 + x = 3,75;
x = 3,75 – 2,8;
x = 0,95;
3) 6x + 9x – 5,8 = 3,8;
15x = 3,8 + 5,8;
15x = 9,6;
x = 9,6 : 15;
x = 0,64;
4) 7x – 2x – 3x + 2,73 = 4,49;
2x = 4,49 – 2,73;
2x = 1,76;
x = 1,76 : 2;
x = 0,88.