Question

considerando as matrizes A= [ 2 3 6 ]. B =[ 1 2 4] C = [0 4 2 ]
determine : a) A+B- c
b) A-B-C

Answer 1

As matrizes $\mathbf{A}$, $\mathbf{B}$ e $\mathbf{C}$ são:

$\mathbf{A}=\left[ \begin{array}{ccc} 2 & 3 & 6 \end{array} \right]\\ \\ \mathbf{B}=\left[ \begin{array}{ccc} 1 & 2 & 4 \end{array} \right]\\ \\ \mathbf{C}=\left[ \begin{array}{ccc} 0 & 4 & 2 \end{array} \right]$


$\text{a)}$

$\mathbf{A}+\mathbf{B}-\mathbf{C}\\ \\ =\left[ \begin{array}{ccc} 2 & 3 & 6 \end{array} \right]+\left[ \begin{array}{ccc} 1 & 2 & 4 \end{array} \right]-\left[ \begin{array}{ccc} 0 & 4 & 2 \end{array} \right]\\ \\ =\left[ \begin{array}{ccc} \left(2+1-0 \right ) & \left(3+2-4 \right ) & \left(6+4-2 \right ) \end{array} \right]\\ \\ =\left[ \begin{array}{ccc} 2 & 1 & 8 \end{array} \right]$


$\text{b)}$

$\mathbf{A}-\mathbf{B}-\mathbf{C}\\ \\ =\left[ \begin{array}{ccc} 2 & 3 & 6 \end{array} \right]-\left[ \begin{array}{ccc} 1 & 2 & 4 \end{array} \right]-\left[ \begin{array}{ccc} 0 & 4 & 2 \end{array} \right]\\ \\ =\left[ \begin{array}{ccc} \left(2-1-0 \right ) & \left(3-2-4 \right ) & \left(6-4-2 \right ) \end{array} \right]\\ \\ =\left[ \begin{array}{ccc} 1 & -3 & 0 \end{array} \right]$