Exercise algebra.equations.linear.balance

Description
Solve a linear equation using only balance rules.

Derivation

3 == -3*x+24

⇒ algebra.equations.linear.balance.con-left-minus, term=24

-21 == -3*x

⇒ algebra.equations.linear.balance.scale-to-one, factor=-3

7 == x

⇒ algebra.equations.linear.flip

x == 7