Exercise algebra.equations.quadratic.no-abc

Description
solve a quadratic equation without abc-formula

Derivation

x^2-x == 30

⇒ algebra.equations.quadratic.move-left

x^2-x-30 == 0

⇒ algebra.equations.quadratic.nice-factors

(x+5)*(x-6) == 0

⇒ algebra.equations.quadratic.product-zero

x == -5 or x == 6