If a + b = -2 and a - b = 12, find b. 

If $$ {4x^2}={25}^2-{15}^2 $$, then find the value of x.

Factor of $$ {12x^{2}+7y^{2}-12}$$ is__

Find the exact value of the following question:

$$ 1280÷{2^3} + 1220÷{2^2}-182=?$$

The factors of  $$ x^2-2x-15 $$ are: 

Direction: In the following questions two equations numbered I and II are given. You have to solve both the equations and Give answer

Give answer (A) If x > y
Give answer (B) if x ≥ y
Give answer (C) if x<y
Give answer (D) If x ≤ y
Give answer (E) if x=y or the relationship cannot be established.

I. 2x²+11x+12=0
II. 5y²+27y+10=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.x³-371 = 629
II.y³ - 543 = 788 

If one root of the equation Ax²+Bx+C = 0 is two and a half times the others, then which of the following is TRUE?