Solve the following equation for x and give your answer correct to two decimal places :

4x² - 5x - 3 = 0

Solve the following equation for x, giving your answer correct to 3 decimal places :

3x² - 12x - 1 = 0

Solve the following equation for x, giving your answer correct to 3 decimal places :

2x² + 11x + 4 = 0

Solve the following equation and give your answer correct to 3 significant figures :

5x² - 3x - 4 = 0