The correct option is C Both x=3,4 are solutions of the equation
Let f(x)=x2−7x+12=0 be the quadratic equation
Now x=3.x=4 are the solutions, if f(3)=0,f(4)=0
Therefore, f(3)=32−7(3)+12
=9−21+12
=0 and
and f(4)=42−7(4)+12
=16−28+12
=0
Therefore x=3,x=4 are the solutions of the given equation.