Ответ:
- \(3x=28-x\)
\(3x+x=28\)
\(4x=28\)
\(x=7\). - \(6x-9=-x-10\)
\(6x+x=9-10\)
\(7x=-1\)
\(x=-\frac{1}{7}\). - \(0,7-0,2x=0,3x-1,8\)
\(0,7+1,8=0,3x+0,2x\)
\(2,5=0,5x\)
\(x=5\). - \(12-4(x-3)=39-9x\)
\(12-4x+12=39-9x\)
\(24-4x=39-9x\)
\(5x=15\)
\(x=3\). - \(9(x-1)=x+15\)
\(9x-9=x+15\)
\(8x=24\)
\(x=3\). - \((1,1x+14)-(5x-8)=25\)
\(1,1x+14-5x+8=25\)
\(-3,9x+22=25\)
\(-3,9x=3\)
\(x=-\frac{10}{13}\).
Ответ: 1) \(x=7\); 2) \(x=-\frac{1}{7}\); 3) \(x=5\); 4) \(x=3\); 5) \(x=3\); 6) \(x=-\frac{10}{13}\).
