How could Beis Hillel (BH) learn two rulings from 1 pasak?
On Berachos 11a, Beis Hillel (BH) and Beis Shammai (BS) disagree regarding the appropriate position for reciting the Shema. BH say that any position is okay. BS say that one should lie down for the morning Shema and stand for the evening Shema. BS base their ruling on uv'shachb'cha uvchumecha, but BH say that this teaches us the appropriate time to say the Shema, not the position.
BH learn that any position is okay from uv'lecht'cha vaderech. BS learn from this that a groom is exempt from reciting the Shema on his wedding night. The gemara asks where BH learns this exemption. They say that they learn it also from uv'lecht'cha vaderech.
Beis Hillel sees two Halachos in two different nuances of the verse. The word used is " b'Lech'ticha ba'Derech," "[And you shall speak in them...] in your walking on the way." The verse could have said, " b'Leches ba'Derech," [And you shall speak in them...] in walking on the way" (because we know the verse is addressing "you" because it already said, "And you shall speak in them").
From the base word, "b'Leches," and from the apparently extra addition, "b'Lechti'*cha*," Beis Hillel was able to learn two Halachos. This is the intention of the Gemara in its conclusion, "Me'meilah Shema Mina."
All the best,
Yisroel Shaw