Exercise algebra.equations.quadratic.no-abc
Description
solve a quadratic equation without abc-formula
Derivation
x^2-7*x+49/4 == 2*(x+4)
⇒ algebra.equations.linear.distr-timesx^2-7*x+49/4 == 2*x+8
⇒ algebra.equations.quadratic.move-leftx^2-9*x+17/4 == 0
⇒ algebra.equations.quadratic.prepare-splitx^2-9*x+81/4 == 16
⇒ algebra.equations.quadratic.left-square(x-9/2)^2 == 16
⇒ algebra.equations.coverup.powerx-9/2 == 4 or x-9/2 == -4
⇒ algebra.equations.coverup.onevar.minus-leftx == 17/2 or x-9/2 == -4
⇒ algebra.equations.coverup.onevar.minus-leftx == 17/2 or x == 1/2