lǎo / shī / xiān / jiǎng / tōng / jiě / de / qiú / fǎ / zài / shuō / míng / zěn / yàng / zhǎo / dào / fú / hé / tiáo / jiàn / de / tè / jiě

老师先讲通解的求法，再说明怎样找到符合条件的特解。

The teacher first explained how to find the general solution, then showed how to find a particular solution that meets the conditions.