2x + 21 - x = 3 হলে, x = কত?

প্রশ্ন: 2x + 21 - x = 3 হলে, x = কত?সমাধান:2x + 2/2x = 3⇒ {(2x)2 + 2}/2x = 3⇒ (2x)2 + 2 = 3 . 2x⇒ a2 + 2 = 3a [2x = a ধরে]⇒ a2 - 3a + 2 = 0⇒ a2 - 2a - a + 2 = 0⇒ a(a - 2) - 1(a - 2) = 0⇒ (a - 1) (a - 2) = 0হয়,a - 1 = 0⇒ a = 1⇒ 2x = 20∴ x = 0অথবা,a - 2 = 0⇒ a = 2⇒ 2x = 21∴ x = 1∴ নির্ণেয় সমাধান x = (0, 1)