Please answer the 15th question

Please answer the 15th question 12. If a+b+c = 9; 14. If 13. iisdammam.edu.sa ab+ bc+ac = 26; find a2+b2+c2 I ; find a3 + b3 + c3 - 3abc 6 ; ab+ bc + ca — 28 find the value of a3 + 133 15. Show that 2x + I is a factor of polynomial 2x3 + x2 - 6x —3. Hence the factorise the polynomial 16. Find common factor in polynomials x2 + 8x + 15 and x2 + 3x — 10 x 4 - 13x3 + 29x2 + 12x — 30 by q(x) = x + ; Also find what should 17. Divide p(x) ¯ be subtracted from p(x) so that it is divisible by q(x) 18. The volume ofa cuboid is p(x) = x3 + 13x2 + 32x + 20 ; find the possible expressions for dimensions of the cuboid.