Exercise algebra.equations.quadratic.no-abc

Description
solve a quadratic equation without abc-formula

Derivation

75 == 9*x^2-6

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

81 == 9*x^2

⇒ algebra.equations.coverup.times

9 == x^2

⇒ algebra.equations.coverup.power

3 == x or -3 == x

⇒ algebra.equations.linear.flip

x == 3 or -3 == x

⇒ algebra.equations.linear.flip

x == 3 or x == -3