P=(1+1)/6=2/6=1/3
Ответ: 1/3
8*2/3:(5/6x-5/3)-19/40=21/40
8*2/3:5x-10/6-19/40=21/40
8*2/3:5x-10/6-19/40=21/40
8*2/3*6/5x-10-19/40=21/40
8*2*2/5x-10-19/40=21/40
32/5x-10=19/40=21/40
32/5x-10=21/40+19/40
32/5x-10=21+19/40
21/5x-10=40/40
32/5x-10=1
32=5x-10
-5x=-10-32
-5x=-42
x=42/5
x=8 2/5
Ответ: 8 2/5
(5х+2х)•14=294
7х * 14 = 294
7х=294 :14
7х=21
х=21:7
х=3
проверка (5*3 + 2*3) *14=294
(15+6)*14=294
21*14=294
294=294