Question 62975

(3x-a)(x-2)(x-7) = 3x^3 - 32x^2 + 81x - 70

==> (3x-a)(x^2 - 2x - 7x + 14) = 3x^3 - 32x^2 + 81x - 70

==> (3x-a)(x^2 - 9x + 14) = 3x^3 - 32x^2 + 81x - 70

==> 3x^3 - 27x^2 + 42x - ax^2 + 9ax - 14a = 3x^3 - 32x^2 + 81x - 70

==> 3x^3 - x^2(27 + a) + x(42 + 9a) - 14a = 3x^3 - 32x^2 + 81x - 70

Comparing the like terms we get,

27 + a = 32                  
==> a = 32 - 27
==> a = 5


a = 5

Good Luck!!!