Answer
$a = (3.00~m/s^2)~\hat{i}-(4.00~m/s^2)~\hat{j}+(2.00~m/s^2)~\hat{k}$
Work Step by Step
We can express the force in unit-vector notation:
$F = (6.00~N)~\hat{i}-(8.00~N)~\hat{j}+(4.00~N)~\hat{k}$
We can find the acceleration:
$F = ma$
$a = \frac{F}{m}$
$a = (\frac{1}{2.00~kg})[(6.00~N)~\hat{i}-(8.00~N)~\hat{j}+(4.00~N)~\hat{k}]$
$a = (3.00~m/s^2)~\hat{i}-(4.00~m/s^2)~\hat{j}+(2.00~m/s^2)~\hat{k}$