4+(-2 5/10)

Compute step by step:

• 5/10 = 1/2, so -2 5/10 = -2 1/2 = -5/2.
• 4 + (-5/2) = 4 - 5/2 = 8/2 - 5/2 = 3/2.

Answer: 3/2, which is 1.5 in decimal.