Is the ordered pair $(2,-1)$ a solution to the equation $4x-y=9$?

Solve the system: $y=\frac{2}{3}x-1$ and $3x+2y=7$. Provide the intersection point.

Which quick algebraic test allows you determine whether a two-line system has zero, one, or infinitely many solutions without needing to graph anything?

Solve for $x$: $7-2(x+3)=1$

Rearrange and solve for $x$:

$-2(3x+4)+5=x-7$

Consider the system { ax + by = c ; 2ax + 2by = 2c } for nonzero values: a, b, and c. Determine what the set of solutions will be and explain your results in terms of ordered pairs and lines.

Which method would you choose to solve $\{\begin{array}{c}4x+5y=23\\ x=\frac{1}{2}y+3\end{array}$, and why?

Solve the system of equations: $2(y-x)=10$ and $-x+3y=1$.

Solve by elimination: $9x-6y=3$ and $3x+4y=11$. What is the final solution?