Exercise algebra.equations.quadratic.no-abc

Description
solve a quadratic equation without abc-formula

Derivation

2*x^2+4*x-8 == 0

⇒ algebra.equations.quadratic.scale

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

⇒ algebra.equations.quadratic.prepare-split

x^2+2*x+1 == 5

⇒ algebra.equations.quadratic.left-square

(x+1)^2 == 5

⇒ algebra.equations.coverup.power

x+1 == sqrt 5 or x+1 == -sqrt 5

⇒ algebra.equations.coverup.onevar.plus

x == -1+sqrt 5 or x+1 == -sqrt 5

⇒ algebra.equations.coverup.onevar.plus

x == -1+sqrt 5 or x == -1-sqrt 5