Tính

To solve these expressions, we will simplify each one step by step:

1) 4/-5 + 12/13 - 4/13 - (-2/5)
To add fractions, we need a common denominator. The least common multiple of 5 and 13 is 65.
So, we rewrite the expression with the common denominator:
(4*(-13))/(5*(-13)) + (12*5)/(13*5) - (4*5)/(13*5) - (-2*13)/(5*13)
= -52/(-65) + 60/65 - 20/65 + 26/65
= (52/65) + (60/65) - (20/65) + (26/65)
= (52 + 60 - 20 + 26)/65
= 118/65

2) -6/5 * 1/5 + 1/-2 * 2/5 - 0.5
To multiply fractions, we multiply the numerators and denominators separately.
(-6*1)/(5*5) + (1*(-2))/(1*5) - 0.5
= -6/25 - 2/5 - 0.5
= -6/25 - 10/25 - 0.5
= (-6 - 10)/25 - 0.5
= -16/25 - 0.5
= -16/25 - 12.5/25
= (-16 - 12.5)/25
= -28.5/25

3) 12.5 * 0.6 + 1 1/10 * 3/5 - 0.6 * 2.5
We convert the mixed number 1 1/10 to an improper fraction: (1*10 + 1)/10 = 11/10
12.5 * 0.6 + 11/10 * 3/5 - 0.6 * 2.5
= 7.5 + (11/10 * 3/5) - 1.5
= 7.5 + (11*3)/(10*5) - 1.5
= 7.5 + 33/50 - 1.5
= 7.5 + 33/50 - 75/50
= 7.5 + (33 - 75)/50
= 7.5 - 42/50
= 7.5 - 21/25
= (7.5*25 - 21)/25
= (187.5 - 21)/25
= 166.5/25
= 333/50

So, the simplified expressions are:
1) 118/65
2) -28.5/25
3) 333/50