For what value of k, system of equations 5x + 2y = k, 10x + 4y = 3 has infinitely many solutions?

The system of equations $a_{1} x+b_{1} y+c_{1}=0$, $a_{2} x+b_{2} y+c_{2}=0$ will have infinite solutions if

$\frac{a_{1}}{a_{2}}=\frac{b_{1}}{b_{2}}=\frac{c_{1}}{c_{2}}$

$\Rightarrow \frac{5}{10}=\frac{2}{4}=\frac{-k}{-3}$

$\Rightarrow \frac{1}{2}=\frac{k}{3} \Rightarrow k=\frac{3}{2}$