 <translate> Give the step-by-step reasoning process and then the final answer. Sasha heard that planting trees helps to reduce the local temperature. For each tree planted, the temperature drops .1 degree. A tree costs $6 to plant. If she got the local temperature to drop from 80 to 78.2, how much did it cost to plant the trees? <yor> Ṣàlàyé bí wọ́n ṣe ń ronú lẹ́ẹ̀kan-lẹ́ẹ̀kan, kó o sì wá sọ ìdáhùn tó o máa fún wọn. Sasha ti gbọ́ pé gbígbin igi máa ń dín ooru kù. Bí wọ́n bá gbin igi kan, ńṣe ni ooru á máa dín kù sí i. Owó dọ́là mẹ́fà ni wọ́n fi ń gbin igi kan. Tó bá jẹ́ pé ó mú kí ooru ibẹ̀ lọ sílẹ̀ láti 80 sí 78.2, kí ni iye tí ó ná láti gbin àwọn igi náà? 