Processing Math: Done

From Förberedande kurs i matematik 1

The equation (x−3)(x−3)=0  is a second-degree equation which has x=3 and x=3  as roots; when x=3, the first factor is zero and when x=3  the second factor is zero.

If we expand the equation's left-hand side, we get the equation in standard form,

(x−3)(x−3)=x2−3x−3x+33=x2−(3+3)x+33=0.

Note: the general answer is

ax2−(3+3)ax+33a=0

where a=0 is a constant.