Exercise algebra.equations.linear.balance
Description
Solve a linear equation using only balance rules.
Derivation
![](http://ideas.cs.uu.nl/images/external.png)
-21+3*x == 0
⇒ algebra.equations.linear.balance.smart-div, factor=3-7+x == 0
⇒ algebra.equations.linear.balance.con-right-plus, term=7x == 7