-0,4x-1,8=2+0,5x -2(x+8)+9=-3(x-8) 16/21x - 2,48=3/7x-1,18
1)-0,4x-1,8=2+0,5x
-0.4x-0,5x=2+1.8
-0.9x=3.8
x=-38/9
2)-2(x+8)+9=-3(x-8)
-2x-16+9=-3x+24
-2x-7=-3x+24
-2x+3x=24+7
x=31
3)16/21x - 2,48=3/7x-1,18
16/21x-62/25=3/7x-59/50
800x-2604=450x-1239
800x-450x=-1239+2604
350x=1365
x=39/10