①17x+3.4=27.2
②2.5x-6=18.5
③2.1+3x=12.6
④2.7x-0.7x=20
⑤5.6x+4x=17.28
⑥5(x+4.1)=36.5
4(x+0.3)=4.8
1.2x-0.4x=9.6
1.5×8-2x=6
7.9×0.97.9 12.3×112.3÷1 9.6÷1.19.6