-0.15(x-4)=9.9-0.3(x-1)
-0.15х+0.6=9.9-0.3х+0.3; -0.15х+0.3х=9.9+0.3-0.6; -0.12х=9.6; х=9.6:(-0.12); х=96:(-12) х=8