Find the value of a and b if (x-1) and (x+1) are factors of x⁴+ax³-3x²+2x+b

Given that 10^0.48 = x, 10^0.70 = y and x² = y², then the value of z is close to

If  $${3-5x\over 2x}+{3-5y\over 2y}+{3-5z\over 2z}=0$$ then the value of  $${2\over x}+{2\over y}+{2\over z}$$ is:

If x⁴+2x³+ax²+bx+9 is a perfect square where a and b are positive real numbers, then the value of a and b 

Three positive numbers are in the ratio of 11 : 12 : 15. If the sum of the squares of those numbers is 1960, then the sum of the numbers is

If a-6b = 3 then the value of a³-216b³-54ab is : 

If $$ {x=2-2^{1\over 3}+2 ^{2\over 3}}$$, then the value of $$ {x^{3}-6x^{2}+18x+18}$$.