19x-8x=55 2×(7x-4x)=18 6x+8x=1.4×3 5x+0.1x=50+6.1 7.2x-3.6x=9×0.4 20=5x-3X.
问题描述:
19x-8x=55 | 2×(7x-4x)=18 | 6x+8x=1.4×3 |
5x+0.1x=50+6.1 | 7.2x-3.6x=9×0.4 | 20=5x-3X. |
答
(1)19x-8x=55, 11x=55, 11x÷11=55÷11, &n...