Question

Determine o valor de expressão:
LOG2 8 + LOG5 25 + LOG7 49 +LOG7 1
a)6
b)9
c)4 
d)7
 

Answer 1

$\boxed{log_28+log_525+lo_749+log_71=3+2+2+0=7}$

Answer 2

$log\ _2\ 8 = x\\\\ 2^x = 8\\\\ 2^x = 2^3\\\\ x = 3$

$log\ _5\ 25 = x\\\\ 5^x = 25\\\\ 5^x = 5^2\\\\ x = 2$

$log\ _7\ 49 = x\\\\ 7^x = 49\\\\ 7^x = 7^2\\\\ x = 2$

$log\ _7\ 1 = x\\\\ 7^x = 1\\\\ 7^x = 7^0\\\\ x = 0$

$3+2+2+0 = 7$