The number of irrational roots of the equation (x−1)(x−2)(3x−2)(3x+1)=21 is

(3x−2)(x−1)(3x+1)(x−2)=21⇒3x2−5x+23x2−5x−2=21⇒3x2−5x2−4=21 ⇒ 3x2−5x=±5⇒3x2−5x−5=0 or 3x2−5x+5=0The first equation has irrational roots and the second has imaginary roots.