Exercise algebra.equations.linear.balance

Description
Solve a linear equation using only balance rules.

Derivation

3*x-1 == x+7

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

2*x-1 == 7

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

2*x == 8

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

x == 4