Find the constant term in the binomial expansion of ((2x – frac{3}{x})^{8}).
-
A.
90720 -
B.
1296 -
C.
1120 -
D.
672
Correct Answer: Option A
Explanation
((x)^{n}(x^{-1})^{8 – n} = x^{0})
(x^{n} . x^{-8 + n} = x^{0} implies n – 8 + n = 0)
(2n – 8 = 0 implies n = 4)
Constant term = (^{8}C_{4}(2^{4})(3^{4}) = 70 times 16 times 81)
= (90720)