Solve the following equation using quadratic formula:

x² + 7x = 7

Solve the following equation using quadratic formula:

3x² - x - 7 = 0

Solve the following equation using quadratic formula:

x² - 7x + 3 = 0

Solve for x the quadratic equation x² - 4x - 8 = 0. Give your answer correct to three significant figures.