Exercise algebra.equations.quadratic.no-abc
Description
solve a quadratic equation without abc-formula
Derivation
-(x-2)*(x+6)+4*x == 0
⇒ algebra.equations.linear.distr-times-x^2-4*x+12+4*x == 0
⇒ algebra.equations.linear.merge-x^2+12 == 0
⇒ algebra.equations.quadratic.no-linx^2 == 12
⇒ algebra.equations.coverup.powerx == sqrt 12 or x == -sqrt 12
⇒ algebra.equations.quadratic.simpler-sqrtx == 2*sqrt 3 or x == -2*sqrt 3