Exercise algebra.equations.quadratic.no-abc
Description
solve a quadratic equation without abc-formula
Derivation
![](http://ideas.cs.uu.nl/images/external.png)
x+2 == sqrt 8 or x+2 == -sqrt 8
⇒ algebra.equations.coverup.onevar.plusx == -2+sqrt 8 or x+2 == -sqrt 8
⇒ algebra.equations.coverup.onevar.plusx == -2+sqrt 8 or x == -2-sqrt 8
⇒ algebra.equations.quadratic.simpler-sqrtx == -2+2*sqrt 2 or x == -2-2*sqrt 2