Exercise algebra.equations.linear.balance

Description
Solve a linear equation using only balance rules.

Derivation

-5 == 2*x+15

⇒ algebra.equations.linear.flip

2*x+15 == -5

⇒ algebra.equations.linear.balance.con-right-minus, term=15

2*x == -20

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

x == -10