Exercise algebra.equations.quadratic.no-abc
Description
solve a quadratic equation without abc-formula
Derivation
![](http://ideas.cs.uu.nl/images/external.png)
4*(10-x^2)+4*x^2+20*x == 0
⇒ algebra.equations.quadratic.same-con-factor10-x^2+x^2+5*x == 0
⇒ algebra.equations.linear.merge10+5*x == 0
⇒ algebra.equations.coverup.onevar.plus5*x == -10
⇒ algebra.equations.coverup.timesx == -2