3X+56=983X=98-563X=42X=140.42X-2.3=1.90.42X=1.9+2.30.42X=4.2X=105X-3×0.6=6.25X=6.2+3×0.65X=8X=8/54×5.1+2X=60.42X=60.4-4×5.12X=40X=20看来你这个知识点没掌握,希望你再认真学一下,掌握好如有帮助,请采纳!