Exercise algebra.equations.quadratic.no-abc

Description
solve a quadratic equation without abc-formula

Derivation

4-x^2/10 == 6

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

x^2/10 == -2

⇒ algebra.equations.coverup.numerator

x^2 == -20

⇒ algebra.equations.coverup.power

false