The quadratic formula can be used to solve quadratic equations, equations in the form ax2 + bx +c = 0. Remember that either 'b' and 'c' may be equal to zero, in which case the formula will be ax2 + bx or ax2 + c. If a = 0, the equation will be linear, which are solved differently. If c = 0, the equation is very simple to solve, as it will equal x(ax + b) = 0 in which case the solutions are x=0 and x=-b/a. (See Factorisation and simplification).
2x2 + 6x - 14 = 0