Exercise algebra.equations.quadratic.no-abc

Description
solve a quadratic equation without abc-formula

Derivation

Final term is not finished

9 == 6-2*x or 6-2*x == -9

⇒ algebra.equations.coverup.onevar.minus-right

-3 == 2*x or 6-2*x == -9

⇒ algebra.equations.coverup.times

-3/2 == x or 6-2*x == -9

⇒ algebra.equations.linear.flip

x == -3/2 or 6-2*x == -9