SAGE : Solving Equation

1. Solve the equation $x^2+4x-5=0$ for $x$.


2. Solve the equation $\frac{2t^2+3t-4}{t-1}=1$, and show the solution in "pretty print".


3. Solve the system of equations \begin{equation} \left\{ \begin{aligned} 3x+4y &= 8 \\ 2x-5y &= 4 \end{aligned} \right. \end{equation}


4. Create the Quadratic Formula by solving $ax^2+bx+c=0$ for $x$.