To simplify this expression, we first need to multiply the numerator and denominator by the conjugate of the denominator, which is 1-i.

(1-i)(8+3i) = 8 + 3i - 8i - 3i^2
= 8 + 3i - 8i + 3 (since i^2 = -1)
= 11 - 5i

Now, the numerator is 11 - 5i.

Denominator is:
1 + i

Now, multiply both the numerator and denominator by the conjugate of the denominator, which is 1 - i.

(1 - i)(1 + i) = 1 - i + i - i^2
= 1 - (-1)
= 2

So, the denominator is 2.

Therefore, the simplified expression is:

(11 - 5i) / 2