3/7 and -4

Postulate :Every quadratic of aX

^{2}+ bX + c has roots of m, n if and only if aX

^{2 }+bX +c can be factored into ( x -m ) ( X -n) accordingly :

f(x) = ( X +4) ( X -3/7) = X

^{2 }+ 4X -3/7X - 12/7 7X

^{2}+28X - 3X - 12= 7X

^{2}+ 25X - 12