Respuesta :

Answer:

Step-by-step explanation:

a.

G.M. between between 15 and 20=√(15×20)

=√(300)

=√(100×3)

=10√3

b.

G.M. between 18 and 30

=√(18×30)

=√(3×3×2×2×3×5)

=3×2√15

=6√15