Question 112410
I feel the question should read 

sqrt (144 x^10 y^12 z^18}

= sqrt(144)*sqrt(x^10)*sqrt(y^12)*sqrt(z^18)

= 12 * x^5 * y^6 * z*9 [ while taking sqrt, the exponents become halved]

= 12x^5 y^6 z^9



Good luck!!!