Exercise algebra.equations.quadratic.no-abc
Description
solve a quadratic equation without abc-formula
Derivation
![](http://ideas.cs.uu.nl/images/external.png)
10*x+20 == 0
⇒ algebra.equations.coverup.onevar.plus10*x == -20
⇒ algebra.equations.coverup.timesx == -2
Description
solve a quadratic equation without abc-formula