0.8x+0.7=7.9 :x=0.6:
3.5x+0.8=2.2
7x+3×16=69 8:x=4:0.8
5.4+2x=8.6 4.2×(x﹣5)=63 16:x=0.75:
① ②
①
②
③ =3:2
①1.5x-2.8=4.7
③12: =