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