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 -sqrt 7 == 7+2*x
⇒ algebra.equations.coverup.onevar.plus7+2*x == sqrt 7 or -7-sqrt 7 == 2*x
⇒ algebra.equations.coverup.times7+2*x == sqrt 7 or (-7-sqrt 7)/2 == x
⇒ algebra.equations.linear.flip7+2*x == sqrt 7 or x == (-7-sqrt 7)/2
⇒ algebra.equations.quadratic.distr-div7+2*x == sqrt 7 or x == -7/2-sqrt 7/2