Exercise algebra.equations.quadratic.no-abc
Description
solve a quadratic equation without abc-formula
Derivation
2*(10-x^2) == -x*(2*x+10)
⇒ algebra.equations.linear.distr-times20-2*x^2 == -2*x^2-10*x
⇒ algebra.equations.quadratic.cancel20 == -10*x
⇒ algebra.equations.coverup.times-2 == x
⇒ algebra.equations.linear.flipx == -2