Exercise algebra.equations.quadratic.no-abc

Description
solve a quadratic equation without abc-formula

Derivation

81 == (6-2*x)^2

⇒ algebra.equations.coverup.power

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

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

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

⇒ algebra.equations.coverup.times

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

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

-3/2 == x or 15 == 2*x

⇒ algebra.equations.coverup.times

-3/2 == x or 15/2 == x

⇒ algebra.equations.linear.flip

x == -3/2 or 15/2 == x

⇒ algebra.equations.linear.flip

x == -3/2 or x == 15/2