a) 1,5.(1/3-2/3)
To simplify this expression, we first need to perform the subtraction inside the parentheses:
1/3 - 2/3 = -1/3

Now, we multiply -1/3 by 1,5:
-1/3 * 1,5 = -1,5/3

Therefore, the simplified expression is -1,5/3.

b) 9/10.23/11-1/11.9/10+9/10
To simplify this expression, we need to perform the multiplications and additions/subtractions in the correct order, following the PEMDAS (Parentheses, Exponents, Multiplication and Division, Addition and Subtraction) rule.

First, let's perform the multiplications:
9/10 * 23/11 = 207/110
1/11 * 9/10 = 9/110

Now, let's perform the additions/subtractions:
207/110 - 9/110 = 198/110

Finally, let's simplify the fraction:
198/110 = 99/55

Therefore, the simplified expression is 99/55.

c) 2/5 + 3/5 : -3/2 + 1/2
To simplify this expression, we need to perform the division and addition/subtraction in the correct order.

First, let's perform the division:
3/5 : -3/2 = 3/5 * -2/3 = -6/15 = -2/5

Now, let's perform the addition:
2/5 + -2/5 = 0/5 = 0

Therefore, the simplified expression is 0.

d) 1 2/5 - (-1/2)^2 + 7/10
To simplify this expression, we need to perform the exponentiation, subtraction, and addition in the correct order.

First, let's perform the exponentiation:
(-1/2)^2 = 1/4

Now, let's perform the subtraction and addition:
1 2/5 - 1/4 + 7/10 = 7/5 - 1/4 + 7/10

To add or subtract fractions, we need a common denominator. The least common denominator (LCD) for 5, 4, and 10 is 20.

Converting the fractions to have a denominator of 20:
7/5 = 28/20
1/4 = 5/20
7/10 = 14/20

Now, let's perform the addition and subtraction:
28/20 - 5/20 + 14/20 = 37/20

Therefore, the simplified expression is 37/20.