1) log(√7)(1/7)+3^log₃7=log(7^(1/2)7⁻¹+7=-2log₇7+7=-2+7=5.
2) √(25^(1/log⁶5)+49^(1/log₈7))=√(5^2log₅6+7^2log₇8)=
=√(5^log₅6²+7^log₇8²)=√(6²+8²)=√100=10.
3) 10^(1-lg5)=10*10^(-lg5)=10/10^lg5=10/5=2.
4) log(c)(16c²)=log(c)4⁴+log(c)c²=4log(c)2+2=4*(-3)+2=-10.