If a, b, c are non-zero rational numbers
such that a + b + c = 0, then the roots of the equation
(b+c−a)x2+(c+a−b)x+(a+b−c)=0
are
both rational
both irrational
both purely imaginary
one rational and one irrational
As a + b + c = 0, we can write the equation
2ax2+2bx+2c=0
or
ax2+bx+c=0
Note that x = 1 satisfies this equation and its other root is c/a.