1) 0,5√4*15 а^2= 0,5*2а √15= 1а√15
2) 2,1√100*3 х^4= 2,1*10x^2√3= 21x^2√3
3) √-3c^3= √-3c*c^2= c√-3c
4) √9a^2*b= 3a√b
5) 0,2√225a^2= 0,2*15a= 3a
6) a√18a^2*b= a√9*2a^2*b= a*3*a√2b= 3a^2√2b
7) -b√48ab^2= -b√16*3ab^2= -b*4b√3a= -4b^2√3a
8) √-5m^7= m^3√-5m