Exercise algebra.equations.linear.balance

Description
Solve a linear equation using only balance rules.

Derivation

x+7 == 3*x-1

⇒ algebra.equations.linear.balance.var-right-minus, term=x

7 == 2*x-1

⇒ algebra.equations.linear.balance.con-left-plus, term=1

8 == 2*x

⇒ algebra.equations.linear.balance.scale-to-one, factor=2

4 == x

⇒ algebra.equations.linear.flip

x == 4