(-2/3 + 5/12) + (-0.45)

To add fractions, we need a common denominator. The least common denominator between 3 and 12 is 12.

Converting -2/3 to have a denominator of 12:
-2/3 = -8/12

Therefore, we have (-8/12 + 5/12) + (-0.45)
= (-3/12) + (-0.45)
= -3/12 - 45/100
= -3/12 - 54/120
= -30/120 - 54/120
= -84/120
= -7/10

Therefore, (-2/3 + 5/12) + (-0.45) = -7/10.