How do you solve an equation with x² in it?

Equations with x² in them are called quadratics. There are three methods for solving quadratic equations.

The first is to factorise it if possible

E.g. x²+3x+2 = 0 becomes (x+2)(x+1)=0. 

Since one of these brackets must be worth zero to get the zero on the left-hand side then

either x+2=0 or x+1=0

so x=-2 or x=-1

You can also use the quadratic formula, which is useful if your equation will not factorise.

So if ax²+bx+c=0 then

x=

So if x²+3x+2 = 0 then here a=1, b= 3 and c=2. You then substitute these values into the formula using your calculator to find your answer.

Yet a further method is to complete the square.