Exercise algebra.equations.quadratic.no-abc

Description
solve a quadratic equation without abc-formula

Derivation

12-x^2 == 4*x

⇒ algebra.equations.quadratic.move-left

-x^2-4*x+12 == 0

⇒ algebra.equations.quadratic.nice-factors

(x-2)*(x+6) == 0

⇒ algebra.equations.quadratic.product-zero

x == 2 or x == -6