(i) 2^2/3 * 2^1/5 = 2^{2/3 + 1/5}

= 2^{10/15 + 3/15}

= 2^13/15

(ii) ()⁷ = 3^-21

(iii) 11^1/2/11⁴ = 11^{1/2 – 1/4}

= 11^{2/4 – 1/4}

= 11^1/4

(iv) 7^1/2 * 8^1/2 = 7 * 8^1/2

= 56^1/2