1) 39 : (x * 4 - 25) = 13;
x * 4 – 25 = 39 : 13;
x * 4 – 25 = 3;
x * 4 = 3 + 25;
x * 4 = 28;
х = 28 : 4;
х = 7.
б)120-40
80-32
=48
