Exercise algebra.equations.linear.balance
Description
Solve a linear equation using only balance rules.
Derivation
10*x-30 == 3*x-9
⇒ algebra.equations.linear.balance.var-left-minus, term=3*x7*x-30 == -9
⇒ algebra.equations.linear.balance.con-right-plus, term=307*x == 21
⇒ algebra.equations.linear.balance.scale-to-one, factor=7x == 3