If 2x-1 + 2x+1 = 1280, then find the value of x.	Select the correct option.
A) 0
B) 2
C) 4
D) 9
E) 6
Sol.   2x-1 + 2x+1 = 1280 ⇔ 2x-1 (1+22) = 1280   ⇔ 2x-1 = 1280 / 5= 
<gadget id="calculator">1280 / 5</gadget>
<output>256</output>
256= 28   ⇔ x - 1 = 8 ⇔ x = 9.   Hence, x = 9.   Answer 9
<result>D</result>
If 2x-1 + 2x+1 = 1280, then find the value of x.