Exercise algebra.equations.quadratic.no-abc

Description
solve a quadratic equation without abc-formula

Derivation

(x-7/2)^2 == 2*(x+4)

⇒ algebra.equations.quadratic.distr-square

x^2-7*x+49/4 == 2*(x+4)

⇒ algebra.equations.linear.distr-times

x^2-7*x+49/4 == 2*x+8

⇒ algebra.equations.quadratic.move-left

x^2-9*x+17/4 == 0

⇒ algebra.equations.quadratic.prepare-split

x^2-9*x+81/4 == 16

⇒ algebra.equations.quadratic.left-square

(x-9/2)^2 == 16

⇒ algebra.equations.coverup.power

x-9/2 == 4 or x-9/2 == -4

⇒ algebra.equations.coverup.onevar.minus-left

x == 17/2 or x-9/2 == -4

⇒ algebra.equations.coverup.onevar.minus-left

x == 17/2 or x == 1/2