2. 7/15 - 3/10 =

Find a common denominator for 15 and 10, which is 30.

Convert the fractions: (7*2)/(15*2) - (3*3)/(10*3) = 14/30 - 9/30.

Subtract the numerators: (14 - 9) / 30 = 5/30. Simplify to 1/6.