18.
2^(4m-1) * (1/3)^(2-2m) = 2^(4m-1) (3⁻¹)^(2-2m) =
12^(2m-2) (2² * 3)^(2m-2)
=2^(4m-1-4m+4) * 3^(-2+2m-2m+2)=2³ * 3⁰=8*1=8
Ответ: 8.
23.
80^(2m-3) = (4² * 5)^(2m-3) =4^(4m-6-4m+7)*5^(2m-3-2m+5)=
4^(4m-7) 5^(2m-5) 4^(4m-7) 5^(2m-5)
=4¹ * 5²=100
Ответ: 100
26.
12^(2k-1) = (2*6)^(2k-1) =
10 * 2^(2k-3) 6^(2k-1) 10 * 2^(2k-3) 6^(2k-1)
=0.1 * 2^(2k-1-2k+3) 6^(2k-1-2k+1)=0.1*2² * 6⁰=0.4
Ответ: 0,4