The polynomials and when divided by (x-4) leave the same remainder. Find the value of a.

Let f(x) = ax3 + 3x2 – 3


And,


g(x) = 2x3 - 5x + a


Now,


f(4) = a(4)3 + 3(4)2 – 3


= 64a + 48 - 3


= 64a + 45


And,


g(4) = 2(4)3 – 5(4) + a


= 128 – 20 + a


= 108 + a


According to the question,


f(4) = g(4)


64a + 45 = 108 + a


64a – a = 108 – 45


63a = 63


a = 1


Hence, the value of ‘a’ is 1.


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