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`y = k (x) = (-3)/2 x+5/2`
`⇒ k (x) = (-3)/2 x+5/2`
$\bullet$ `k(2) = (-3)/2 . 2 +5/2=-3+5/2=(-1)/2`
$\bullet$ `k(1/3)=(-3)/2 . 1/3 + 5/2=(-1)/2 +5/2=2`
$\bullet$ `k( (-1)/2) = (-3)/2 . (-1)/2 +5/2=3/4 + 5/2=13/4`
Vậy `k (2)=(-1)/2, k (1/3)=2, k( (-1)/2) = 13/4`