If 7^(x - y) = 343 and 7^(x + y) = 16807, what is the value of x?
Options.
A) 3 B) 4 C) 2 D) 1 E) 7
7^(x - y) = 343 = 7^3   =&gt; x - y = 3 ---------------------------(Equation 1)   7^(x + y) = 16807 = 7^5   =&gt; x + y = 5 ---------------------------(Equation 2)   (Equation 1)+ (Equation 2) =&gt; 2x = 3 + 5= 
<gadget id="calculator">3 + 5</gadget>
<output>8</output>
8=&gt; x = 8/2= 
<gadget id="calculator">8/2</gadget>
<output>4</output>
4   Answer is 4
<result>B</result>
If 7^(x - y) = 343 and 7^(x + y) = 16807, what is the value of x?