Exercise algebra.equations.linear.balance

Description
Solve a linear equation using only balance rules.

Derivation

(x+3)/2 == 5/2*x+15/2

⇒ algebra.equations.linear.balance.remove-div, factor=2

x+3 == 5*x+15

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

3 == 4*x+15

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

-12 == 4*x

⇒ algebra.equations.linear.balance.scale-to-one, factor=4

-3 == x

⇒ algebra.equations.linear.flip

x == -3