1.301
Explanation:
Given:
[tex]\log_a5 \approx 0.699[/tex] and [tex]\log_a2 \approx 0.301[/tex]
Note that from the properties of logarithms,
[tex]\log_a20 = \log_a(5×4)[/tex]
[tex]\:\:\:\:\:\:\:\:\:\:= \log_a(5×2^2)[/tex]
[tex]\:\:\:\:\:\:\:\:\:\:=\log_a5 + \log_a(2)^2[/tex]
[tex]\:\:\:\:\:\:\:\:\:\:=\log_a5 + 2\log_a2[/tex]
[tex]\:\:\:\:\:\:\:\:\:\:\approx 0.699 + 2(0.301)[/tex]
[tex]\:\:\:\:\:\:\:\:\:\:= 1.301[/tex]
