The pair of equations $x=a$ and $y=b$ graphically represent lines which are

The values of $a$ and $b$ for which the following system of equations has infinitely many solutions is 

\( 2x+3y=7\)

\( (a-b)x+(a+2)y=3a \)

Graphically, the pair of equations represents two lines which are:

$6x-3y+10=0$
$2x-y+9=0$

The pair of equations $y=0$ and $y=-7$ has:

Which ordered pair is a solution of the system?

$\left\{\begin{array}{c}2x-y=-2\\ \frac{1}{3}y=x\end{array}\right.$