Cancel Operator

When \(a \ne 0\), there are two solutions to \(ax^2 + bx + c = 0\) and they are $$x = {-b \pm \sqrt{b^2-4ac} \over 2a}.$$

Some math with the cancel operator in mathjax: $$\cancel{2-2}$$

Some math with the cancel operator in mathjax: $$ \frac{2^{\cancel{3}2}}{\cancel{2}1} = 2^2 = 4$$

Some math with the cancel operator in mathml: $$\cancel{2-<!--\; -\; -->2}$$

$$\cancel{2}$$ $$\frac{2^{\cancel{3}2}}{\cancel{2}1}=2^2=4$$