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Math·Algebra·Linear equations in two variables

hard

$5x+4y=3$
$15x+12y=9$

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

$\left(r,-\frac{4r}{5}+\frac{3}{5}\right)$

B

$\left(r,\frac{5r}{4}+\frac{3}{4}\right)$

C

$\left(-\frac{4r}{5}+\frac{3}{5},r\right)$

D

$\left(\frac{r}{3}+3,-\frac{r}{3}+9\right)$