x=(5x^2-30)/5

Solution for x=(5x^2-30)/5 equation:

x in (-oo:+oo)

x = (5*x^2-30)/5 // - (5*x^2-30)/5

x-((5*x^2-30)/5) = 0

(-1*(5*x^2-30))/5+x = 0

(-1*(5*x^2-30))/5+(5*x)/5 = 0

5*x-1*(5*x^2-30) = 0

5*x-5*x^2+30 = 0

5*x-5*x^2+30 = 0

5*(x-x^2+6) = 0

x-x^2+6 = 0

DELTA = 1^2-(-1*4*6)

DELTA = 25

DELTA > 0

x = (25^(1/2)-1)/(-1*2) or x = (-25^(1/2)-1)/(-1*2)

x = -2 or x = 3

5*(x+2)*(x-3) = 0

(5*(x+2)*(x-3))/5 = 0

(5*(x+2)*(x-3))/5 = 0 // * 5

5*(x+2)*(x-3) = 0

( 5 )

5 = 0

x belongs to the empty set

( x+2 )

x+2 = 0 // - 2

x = -2

( x-3 )

x-3 = 0 // + 3

x = 3

x in { -2, 3 }