Номер 1147

(478 + 12) : x = 70;
490 : x = 70;
x = 490 : 70;
x = 7;
(478 + 12) : 7 = 70;
490 : 7 = 70;
70 = 70.

x – (38 – 15) = 64;
x – 23 = 64;
x = 64 + 23;
x = 87;
87 – (38 – 15) = 64;
87 – 23 = 64;
64 = 64.

5 • x = 42 – 12;
5 • x = 30;
x = 30 : 5;
x = 6;
5 • 6 = 30;
42 – 12 = 30;
30 = 30.

x : 4 = 63 – 27;
x : 4 = 36;
x = 36 • 4;
x = 144;
144 : 4 = 36;
63 – 27 = 36;
36 = 36.

64 : x = 47 – 39;
64 : x = 8;
x = 64 : 8;
x = 8;
64 : 8 = 8;
47 – 39 = 8;
8 = 8.

60 + x = 320;
x = 320 – 60;
x = 260;
60 + 260 = 320;
320 = 320.