0,4(x-7)+0,2(2x-9), 4/5x-1/10x+1/2x=2 2/3
0.4 * (x - 7) + 0.2 * (2x - 9) = 0.4x - 2.8 + 0.4x - 1.8 = 0.8x - 4.6
4/5x - 1/10x + 1/2x = 2 2/3
6/5x = 2 2/3
x = 8/3 * 5/6
x = 20/9
x = 2 2/9