Exercise algebra.equations.quadratic.no-abc

Description
solve a quadratic equation without abc-formula

Derivation

x*(x+2) == 8

⇒ algebra.equations.linear.distr-times

x^2+2*x == 8

⇒ algebra.equations.quadratic.move-left

x^2+2*x-8 == 0

⇒ algebra.equations.quadratic.nice-factors

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

⇒ algebra.equations.quadratic.product-zero

x == 2 or x == -4