Answer
$\lt -3, -4 \gt$
Work Step by Step
Here, $|v|=\sqrt{(3/5)^2+(4/5)^2}=\sqrt {1}=1$
The unit vector $\hat{\textbf{u}}$ can be calculated as: $\hat{\textbf{u}}=\dfrac{v}{|v|}$
Now, $\hat{\textbf{u}}=\dfrac{\lt \dfrac{3}{5},\dfrac{4}{5} \gt}{1}= \lt \dfrac{3}{5},\dfrac{4}{5} \gt$
Thus, $-5 \hat{\textbf{u}}=-5\lt \dfrac{3}{5},\dfrac{4}{5} \gt =\lt -3, -4 \gt$
