SSC Quadratic Equations questions

What is the LCM of ($$8x^{3} + 80x^{2} + 200x$$) and ($$4x^{4} + 16x^{3} - 20x^{2}$$)?

If $$(x - 3)^2 + (2x - 5)^3 + (x - 4)^3 = (3x - 9)(2x - 5)(x - 4)$$ , then what is the value of $$x$$ ?

If $$(x - 5)^3 + (x - 6)^3 + (x - 7)^3 = 3 (x - 5) (x - 6) (x - 7)$$, then what is the value of $$x$$?

$$p^3 + q^3 + r^3 - 3pqr = 4$$. If $$a = q + r, b = r + p$$ and $$c = p + q$$, then what is the value of $$a^3 + b^3 + c^3 - 3abc$$?

If $$a^3 - b^3 = 3552$$ and $$(a - b) = 6$$, then $$(a + b)^2 - ab$$ is equal to:

If $$(2x+3)^3+(x-8)^3+(x+13)^3=(2x+3)(3x-24)(x+13)$$, then what is the value of $$x$$ ?

If $$(x + 4)^3 + (2x + 1)^3 + (2x + 5)^3 = (3x+ 12)(2x + 1)(2x + 5)$$, then what is the value of $$x$$?

If $$x^4 + 2x^3 + ax^2 + bx + 9$$ is a perfect square, where a and b are positive real numbers,then the value of a and b are