The value of the product (7- (12/x)) (49+(84/x)+(144/x^2)) at x = 2 is

Question

The value of the product \(\big(7-\frac{12}{x}\big)\big(49+\frac{84}{x}+\frac{144}{x^2}\big)\) at x = 2 is

(a) 0 

(b) 559 

(c) 127 

(d) 128

Answer 1

(c) 127

\(\big(7-\frac{12}{x}\big)\big(49+\frac{84}{x}+\frac{144}{x^2}\big)\) = (7)³ - \(\big(\frac{12}{x}\big)^3\)

= 343 - \(\big(\frac{12}{x}\big)^3\) = 343 - 216 = 127