Exercise algebra.equations.quadratic.no-abc
Description
solve a quadratic equation without abc-formula
Derivation
40 == 9*x^2+30*x+25+(x-5)^2
⇒ algebra.equations.quadratic.distr-square40 == 9*x^2+30*x+25+x^2-10*x+25
⇒ algebra.equations.linear.flip9*x^2+30*x+25+x^2-10*x+25 == 40
⇒ algebra.equations.linear.merge10*x^2+20*x+50 == 40
⇒ algebra.equations.quadratic.same-con-factorx^2+2*x+5 == 4
⇒ algebra.equations.quadratic.move-leftx^2+2*x+1 == 0
⇒ algebra.equations.quadratic.nice-factors(x+1)^2 == 0
⇒ algebra.equations.coverup.powerx+1 == 0
⇒ algebra.equations.coverup.onevar.plusx == -1