The magnitude of sum of three vectors $\overrightarrow{A}, \overrightarrow{B}$ and $\overrightarrow{C}$ representing the sides of a cube of length $A$ is equal to $A$.

(Take, $\sqrt{3}=1.73$)

Suppose $u$ and $v$ are differentiable functions of $x$ and $u\left(1\right)=2, u^{\text{'}}\left(1\right)=0, v\left(1\right)=5, v^{\text{'}}\left(1\right)=-1$.
If the value of $\frac{\text{d}}{\text{d}x}\left(\frac{u}{v}\right)$ at $x=1$ is $\frac{m}{25}$, find $m$.

Suppose $u$ and $v$ are differentiable functions of $x$ and $u\left(1\right)=2, u^{\text{'}}\left(1\right)=0, v\left(1\right)=5, v^{\text{'}}\left(1\right)=-1$.
Find the value of the following derivative at $x=1$.

$\frac{\mathrm{d}}{\mathrm{d}x}(7v-2u)$