Exercise algebra.equations.quadratic.no-abc

Description
solve a quadratic equation without abc-formula

Derivation

4*(10-x^2)+2*x*(2*x+10) == 0

⇒ algebra.equations.quadratic.same-con-factor

2*(10-x^2)+x*(2*x+10) == 0

⇒ algebra.equations.linear.distr-times

20-2*x^2+2*x^2+10*x == 0

⇒ algebra.equations.quadratic.same-con-factor

10-x^2+x^2+5*x == 0

⇒ algebra.equations.linear.merge

10+5*x == 0

⇒ algebra.equations.coverup.onevar.plus

5*x == -10

⇒ algebra.equations.coverup.times

x == -2