Exercise algebra.equations.quadratic.no-abc
Description
solve a quadratic equation without abc-formula
Derivation
0 == 2*(10-x^2)+x*(2*x+10)
⇒ algebra.equations.linear.distr-times0 == 20-2*x^2+2*x^2+10*x
⇒ algebra.equations.quadratic.same-con-factor0 == 10-x^2+x^2+5*x
⇒ algebra.equations.linear.flip10-x^2+x^2+5*x == 0
⇒ algebra.equations.linear.merge10+5*x == 0
⇒ algebra.equations.coverup.onevar.plus5*x == -10
⇒ algebra.equations.coverup.timesx == -2