Grandmother's 4133

Anička went to her grandmother's for spring break. She paid CZK 38 for the trip, which was two-ninths of their savings. She bought a gift for her grandmother for 35.50 CZK and a book for her cousin Míla for 16.70 CZK. How many crowns did she have left to spend if she saved money for the return trip?

Correct answer:

x =  80.8 Kc

Step-by-step explanation:

$$\begin{gathered} 38=\frac{2}{9}\cdot a \\ x=a-35.50-16.70-38 \\ 38=2/9\cdot a \\ x=a-35.50-16.70-38 \\ 2a=342 \\ a-x=90.2 \\ Row2-\frac{1}{2}\cdot Row1\to Row2 \\ 2a=342 \\ -x=-80.8 \\ x=\frac{-80.8}{-1}=80.8 \\ a=\frac{342}{2}=171 \\ a=171 \\ x=\frac{404}{5}=80.8=\frac{404}{5}\text{Kc}=80.8\text{Kc} \end{gathered}$$

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