Exercise algebra.equations.quadratic.no-abc

Description
solve a quadratic equation without abc-formula

Derivation

x*(2*x-4) == 0

⇒ algebra.equations.quadratic.product-zero

x == 0 or 2*x-4 == 0

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

x == 0 or 2*x == 4

⇒ algebra.equations.coverup.times

x == 0 or x == 2