(3/5+1/15)×3 , (7/16-1/4)÷4 ,
1) (3/5+1/15)*3 = ((3*3)/(5*3)+1/15)*3 = ((9+1)/15)*3 = (10/15)*3 = (2/3)*3 = 2 2) (7/16-(1*4)/(4*4))÷4 = ((7-4)/16)÷4 = (3/16)÷4 = (3/(16*4) = 3/64