Exercise algebra.equations.quadratic.no-abc
Description
solve a quadratic equation without abc-formula
Derivation
![](http://ideas.cs.uu.nl/images/external.png)
7+2*x == sqrt 7 or 7+2*x == -sqrt 7
⇒ algebra.equations.coverup.onevar.plus2*x == -7+sqrt 7 or 7+2*x == -sqrt 7
⇒ algebra.equations.coverup.timesx == (-7+sqrt 7)/2 or 7+2*x == -sqrt 7
⇒ algebra.equations.coverup.onevar.plusx == (-7+sqrt 7)/2 or 2*x == -7-sqrt 7
⇒ algebra.equations.coverup.timesx == (-7+sqrt 7)/2 or x == (-7-sqrt 7)/2
⇒ algebra.equations.quadratic.distr-divx == -7/2+sqrt 7/2 or x == -7/2-sqrt 7/2