Question

Resolva as equações a seguir.
a) logx 64 = 2
b) log (x + 1) = 2
c) log (x - 1)2 = log 1
d) log21 (x + 2) + log2 (x + 6) = 1
me ajudem pfvr​

Answer 1

a) logx 64 = 2

x²=64

x²=2⁶

x = 6

b) log (x + 1) = 2

(x+1) = 10²

x+1 = 100

x = 99

c) log (x - 1)2 = log 1

(x-1)² = 1

x-1 = 1

x = 2

d) log21 (x + 2) + log21 (x + 6) = 1

log21 (x+2).(x+6) = 1

(x+2).(x+6) = 21¹

x²+8x+12 = 21

x²+8x-9=0

∆= 64+36 = 100 => √∆=10

x = -8±10/2

x'= -8+10/2= 2/2= 1