Solve x2 - 8x - 9 = 0. Rewrite the equation so that it is of the form x2 + bx = c.

It can be noted from the given that a = 1, b = - 8 and c = - 9. To transpose c to the other side of the equation, all that needs to be done is to add 9 to both sides of the equation,

x² - 8x - 9 + 9 = 0 + 9

The answer would be,

x² - 8x = 9