Answer
Infinitely many solutions and the solution set is\[\left\{ \left( x,y \right),y=3x-5 \right\}\]or\[\left\{ \left( x,y \right),21x-35=7y \right\}\].
Work Step by Step
Substitute\[y=3x-5\]in the equation\[21x-35=7y\] to get:
\[\begin{align}
& 21x-35=7\left( 3x-5 \right) \\
& 21x-35=21x-35 \\
& -35=-35
\end{align}\]
Since\[-35=-35\], it implies the system of the equation having infinitely many solutions. The line coincide and all the points lying on the lines are the solution to the system of equation. The set of solutions is\[\left\{ \left( x,y \right),y=3x-5 \right\}\]or\[\left\{ \left( x,y \right),21x-35=7y \right\}\].
