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