解：9×3+7.2x=6327+7.2x=637.2x=63-277.2x=36x=36/7.2x=5
9×3+7.2x=63，3+0.8x=7，0.8x=4，x=5
9×3+7.2×＝63解:27+7.2×＝637.2×＝63-277.2×＝36×＝36÷7.2×＝5
