Exercise algebra.equations.quadratic.no-abc
Description
solve a quadratic equation without abc-formula
Derivation
![](http://ideas.cs.uu.nl/images/external.png)
2*x^2 == 18
⇒ algebra.equations.coverup.timesx^2 == 9
⇒ algebra.equations.coverup.powerx == 3 or x == -3
Description
solve a quadratic equation without abc-formula