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Math·Algebra·Systems of two linear equations in two variables

hard

$$\begin{gathered} 2x+5y=7 \\ 8x+20y=28 \end{gathered}$$For each real number $r$, which of the following points lies on the graph of each equation in the $xy$-plane for the given system?

A

$\left(r,\frac{-5r+7}{2}\right)$

B

$\left(r,\frac{2r+7}{5}\right)$

C

$\left(\frac{r+7}{4},\frac{-r+28}{4}\right)$

D

$\left(\frac{-5r+7}{2},r\right)$