Question

if x = 2/7 is a root of polynomial f (x) = 2x² - 3x + 7a find the value of a.

Answer 1

2(2/7)2 - 3×2/7+ 7a = 0
= 8/49 - 6/7 +7a = 0
= 8-42/49 +7a = 0
= 7a = 36/49
= a = 36/343.