Solve 2x² + 3x - 7 = 0 with the quadratic formula. Give the roots to 2 decimal places.

Step 1. The numbers. $a = 2$, $b = 3$, $c = -7$.

Step 2. The discriminant. $b^2 - 4ac = 9 - 4 \times 2 \times (-7) = 9 + 56 = 65$.

Step 3. The formula. $x = \dfrac{-3 \pm \sqrt{65}}{4}$, and $\sqrt{65} \approx 8.062$.

Step 4. The roots. $x \approx \dfrac{5.062}{4} \approx 1.27$, or $x \approx \dfrac{-11.062}{4} \approx -2.77$.