Question

3 raiz de 7 elevado á x-2 = x raiz de 7 elevado a 5

Answer 1

³√7^(x-2) = ×√7^5

7^(x-2)/3 = 7^(5/x)

(x-2)/3 = (5/x)

x.(x-2) = 3.5

x² -2x -15 = 0

∆= (-2)² -4.1.(-15)= 4 +60=64 => √∆=8

x = -b ±√∆/2a

x = 2 ± 8/2.1

x' = 2+8/2 = 10/2 = 5 ✓ (RESP)

x" = 2-8/2= -6/2 = -3 (não serve)