5.
a) 3.6x-4.5=15.3 | *10;
36х-45=153;
36х=153+45;
36х=198;
x=6.
б) 0,4(х+1,6) = 3,24;
0.4х+0.64 = 3,24 | *100;
40x+64=324;
40x=324-64;
40x=260;
x=6,5.
в) 5 4/9 - 2/9x = 3 1/3;
-2/9x=3 1/3 - 5 4/9;
-2/9х=3 3/9 - 5 4/9;
-2/9х=-2 8/9;
2/9x=2 8/9;
x=12;