Q.4. 64- 16 pie and 64-16 pie, so the total is 128-32pie.
Q.5. this condition will be true if x = -1/y, for any negative fraction, 1 proves that x^2=x so according to this statement the above inequality cannot be true and 2 states that X^2 > -X this means that X cannot be a negative fraction for this to be true so both prove against the inequality. both are sufficient.
As for Q.3 i am lost in calculations so help with an easy method.