Expert Help with High School Geometry

The value of the operation [9][6] in ${\displaystyle Z_{10}}$ and to write the answer in the form [r] with ${\displaystyle 0\le r<m}$.

Let $\{v_1,v_2,\dots ,v_n\}$ be a basis for a vector space V. Prove that if a linear transformation ${\displaystyle T:V\to V}$ satisfies ${\displaystyle T\left(v_1\right)=0\text{for}i=1,2,\dot{s},n,}$ then T is the zero transformation.
Getting Started: To prove that T is the zero transformation, you need to show that ${\displaystyle T\left(v\right)=0}$ for every vector v in V.
(i) Let v be an arbitrary vector in V such that ${\displaystyle v=c_1{v}_1+c_2{v}_2+\dot{s}+c_n{v}_n.}$
(ii) Use the definition and properties of linear transformations to rewrite ${\displaystyle T\left(v\right)}$ as a linear combination of ${\displaystyle T\left(v_1\right)}$.
(iii) Use the fact that ${\displaystyle T\left(v_i\right)=0}$ to conclude that ${\displaystyle T\left(v\right)=0}$, making T the zero tranformation.

Find an equation of the plane passing through the three points given. $P=(2,0,0),$

$Q=(0,4,0),$

$R=(0,0,2)$