Exercise algebra.equations.quadratic.no-abc

Description
solve a quadratic equation without abc-formula

Derivation

x^2+14*x+49 == 25

⇒ algebra.equations.quadratic.left-square

(x+7)^2 == 25

⇒ algebra.equations.coverup.power

x+7 == 5 or x+7 == -5

⇒ algebra.equations.coverup.onevar.plus

x == -2 or x+7 == -5

⇒ algebra.equations.coverup.onevar.plus

x == -2 or x == -12