4.2×0.35+0.42×3.5+0.042×35＝4.2×0.35+4.2×0.35+4.2×0.35＝4.2×（0.35+0.35+0.35）＝4.2×1.05＝4.41。
4.2x0.35+0.42x3.5＋0.042x35＝0.42x3.5＋0.42x3.5＋0.42x3.5＝0.42x（3.5+3.5+3.5）＝0.42x11.5＝4.41＝
