Exercise algebra.equations.quadratic.no-abc

Description
solve a quadratic equation without abc-formula

Derivation

12 == 2*(x^2-3)

⇒ algebra.equations.coverup.times

6 == x^2-3

⇒ algebra.equations.coverup.onevar.minus-left

9 == x^2

⇒ algebra.equations.coverup.power

3 == x or -3 == x

⇒ algebra.equations.linear.flip

x == 3 or -3 == x

⇒ algebra.equations.linear.flip

x == 3 or x == -3