1. **Problem:** Solve the first equation using the Quadratic Formula: $4x^2+11x-20=0$. 2. **Formula:** For $ax^2+bx+c=0$, the Quadratic Formula is $$x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}$$. 3. **Identify the coefficients:** Here, $a=4$, $b=11$, and $c=-20$. 4. **Substitute into the formula:** $$x=\frac{-11\pm\sqrt{11^2-4(4)(-20)}}{2(4)}$$ 5. **Simplify inside the square root:** $$x=\frac{-11\pm\sqrt{121+320}}{8}$$ $$x=\frac{-11\pm\sqrt{441}}{8}$$ $$x=\frac{-11\pm 21}{8}$$ 6. **Find both solutions:** $$x=\frac{-11+21}{8}=\frac{10}{8}$$ $$x=\frac{10}{8}=\frac{5}{4}$$ $$x=\frac{-11-21}{8}=\frac{-32}{8}$$ $$x=-4$$ 7. **Final answer:** The solutions are $x=\frac{5}{4}$ and $x=-4$.