Question

7 mũ x + 7 mũ x + 2 + 7 mũ x +3=2751

Answer 1

\(7^x\) + \(7^{x+2}\) + \(7^{x+3}\) = 2751

\(7^x\).( 1 + 7² + 7³) = 2751

\(7^x\).393  = 2751

  7\(^x\) = 2751 : 393

 7\(^x\)  = 7

   \(x\) = 1

Answer 2

7x + 7�+27x+2 + 7�+37x+3 = 2751

7�7x.( 1 + 72 + 73) = 2751

7�7x.393  = 2751

  7�x = 2751 : 393

 7�x  = 7

   $x$ = 1