Đáp án:
$\\$
`c,`
`P = (3/5 - 0,2) × (0,5 - 4/5)`
`-> P = (3/5-1/5) × (1/2 - 4/5)`
`-> P = 2/5 × (5/10 - 8/10)`
`-> P = 2/5 × (-3)/10`
`->P= (-3)/25`
Vậy `P=(-3)/25`
$\\$
`c,`
`C = 1/2 × 1/(-3) + 1/(-3) × 1/4 + 1/4 × 1/(-5) + 1/(-5) × 1/6`
`-> C = (1/2 × (-1)/3 + (-1)/3 × 1/4) + (1/4 × (-1)/5 + (-1)/5 × 1/6)`
`-> C = (-1)/3 × (1/2 + 1/4) + (-1)/5 × (1/4 + 1/6)`
`->C = (-1)/3 × (2/4 + 1/4) + (-1)/5 × (3/12 + 2/12)`
`->C = (-1)/3 × 3/4 + (-1)/5 × 5/12`
`->C = (-1)/4 + (-1)/12`
`-> C =(-3)/12 + (-1)/12`
`->C=(-1)/3`
Vậy `C=(-1)/3`
