Exercise algebra.equations.quadratic.no-abc

Description
solve a quadratic equation without abc-formula

Derivation

(3*x+5)^2+(x-5)^2 == 40

⇒ algebra.equations.quadratic.distr-square

9*x^2+30*x+25+(x-5)^2 == 40

⇒ algebra.equations.quadratic.distr-square

9*x^2+30*x+25+x^2-10*x+25 == 40

⇒ algebra.equations.linear.merge

10*x^2+20*x+50 == 40

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

x^2+2*x+5 == 4

⇒ algebra.equations.quadratic.move-left

x^2+2*x+1 == 0

⇒ algebra.equations.quadratic.nice-factors

(x+1)^2 == 0

⇒ algebra.equations.coverup.power

x+1 == 0

⇒ algebra.equations.coverup.onevar.plus

x == -1