Exercise algebra.equations.quadratic.no-abc

Description
solve a quadratic equation without abc-formula

Derivation

7 == (7+2*x)^2

⇒ algebra.equations.coverup.power

sqrt 7 == 7+2*x or -sqrt 7 == 7+2*x

⇒ algebra.equations.coverup.onevar.plus

-7+sqrt 7 == 2*x or -sqrt 7 == 7+2*x

⇒ algebra.equations.coverup.times

(-7+sqrt 7)/2 == x or -sqrt 7 == 7+2*x

⇒ algebra.equations.coverup.onevar.plus

(-7+sqrt 7)/2 == x or -7-sqrt 7 == 2*x

⇒ algebra.equations.coverup.times

(-7+sqrt 7)/2 == x or (-7-sqrt 7)/2 == x

⇒ algebra.equations.linear.flip

x == (-7+sqrt 7)/2 or (-7-sqrt 7)/2 == x

⇒ algebra.equations.linear.flip

x == (-7+sqrt 7)/2 or x == (-7-sqrt 7)/2

⇒ algebra.equations.quadratic.distr-div

x == -7/2+sqrt 7/2 or x == -7/2-sqrt 7/2