15 21 33 squareroot 2 3 squareroot 35Solution15 3213 To rati

#15, #21

3/3 squareroot 2 3 squareroot 3/5

15. 3/2^1/3

To rationalising multiply and divide with 2^2/3

3*2^2/3 /(2^1/3*2^2/3)

=3*2^2/3/2

= 3(4)^1/3

21. (3/5)^1/3

rationalise the den. by multiplying num. and den. by 5^2/3

(3^1/3*5^2/3) /(5^1/3*5^2/3)

=(3^1/3*25^1/3)/5

= (75)^1/3/5