1.18^n=(2*3*3)^n=2^n*3^n*3^n
=5*6*6=180
2.x^2n=4 => x^n=2 => (x^n)^5=32 => x^5n=32
3.?
10^(2m+3n)=(10^m)^2*(10^n)^3
=25*216=5400
4.-ab(a^2b^5-ab^3-b)
=-ab^2[(ab^2)^2-ab^2-1]
=6[36+6-1]=6*41=246
5.(x+3)(x+a)=x^2+(a+3)x+3a=x^2-2x-15K =>
a+3=-2 3a=-15K => a=-5,K=1