How to Evaluate?

0.5 + (-3 x -2^2) =

0.5 + (-3 x 4) =

0.5 + (-12) =

0.5 - 12 = - 11.5

$k+np^2$

=$0.5+(-3)\times(-2)^2$

=$0.5+(-3)\times4$

=$0.5-12$

=$-11.5$