If one root of the equation $$ {Ax^2+Bx+C=0}$$ is two and a half times the others, then which of the following is True?

Find the exact value of the following question:

$$ 8\sqrt{?}÷14×3+9=21$$

Find the exact value of the following question:

$$ 3{1\over2} × 3 {1\over 7}+ 5{3\over4}÷{46\over3}=?$$

Direction: In the following questions two equations numbered I and II are given. You have to solve both the equations and give answer.
(A) x>y
(B) x≥y
(C) x˂y
(D) x≤y
(E) x=y or the relations ship cannot be established

 I. x²- 1 = 0
II. y²+ 4y + 3 = 0. 

Direction: In the following questions two equations numbered I and II are given. You have to solve both the equations and give answer.
(A) x>y
(B) x≥y
(C) x˂y
(D) x≤y
(E) x=y or the relations ship cannot be established

 I. x²-7x + 12 = 0
II. y² - 12y + 32 = 0 

If $$ {x^2-12x+33=0}$$, then what is the value of $${(x-4)^2+[{1\over({x-4})^2}}]$$.

If α and β are the roots of equation $$ {x^2-2x+4=0}$$, then what is the equation whose roots are ${α^3}\over{β^2}$$ and $${β^3}\over{α^2}$$.

Factor of $$ {ab-a-b+1}$$ is