Exercise algebra.equations.quadratic.no-abc

Description
solve a quadratic equation without abc-formula

Derivation

4*x == 12-x^2

⇒ 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