Помагите пожалуйста решать уранения

1) 2.5*(4.3-2.1)+10х=17.3 2.5*2.2+10x=17.3 5.5+10x=17.3 10x=-5.5+17.3 10x=11.8 x=11.8/10 x=1.18 2) 100x-8.7*(21.3+8.7)=0 100x-8.7*30=0 100x-261=0 100x=261 x=261/100 x=2.61 3) (15.1+284.9)*0.1-1000x=10.3 300*0.1-1000x=10.3 30-1000x=10.3 -1000x=-30+10.3 1000x=19.7 x=19.7/1000 x=0.0197 4) (237.9+42.1)*0.25-100x=11.2 280*0.25-100x=11.2 70-100x=11.2 -100x=-70+11.2 -100x=-58.8 100x=58.8 x=58.8/100 x=0.588

2) 100х=9,92 х=0,0992 2)100х-185,31-75,69=0 100х=261 х=2,61