Solve \(7^x + 7^{x + 1} + 7^{x + 2} + 7^{x + 3} = 2800\)
= 7^x + 7 * 7^x + 49 * 7^x + 343 * 7^x = 2800
= 400* 7^x = 2800
7^x = 7
x = 1
+36916 
