Решите уравнения 1) 10 * х = 8 * 25 2) х : 20 = 4800 : 80 3) (х - 380) * 50 = 2000 4) (х + 8) : 70 = 4 5) 640 : (25 - х) = 40 6) 2700 : (х - 12) = 90

1)10•x=8•25
10•x=200
x=200:10
x=20

2)x:20=4800:80
x:20=60
x=20•60
x=1200

3)(x-380)•50=2000
(x-380)=2000:50
(x-380)=40
x=380+40
x=420

4)(x+8):70=4
(x+8)=70•4
(x+8)=280
x=280-8
x=272

5)640:(25-x)=40
25-x=640:40
25-x=16
x=25-16
x=9

6)2700:(x-12)=90
x-12=2700:90
x-12=30
x=30+12
x=42