Math Snap
PROBLEM
If possible, find , and . (If not possible, enter IMPOSSIBLE in any cell of the matrix.)
$$A=\left[\begin{array}{rr}
6 & -2 \\
2 & 5 \\
-3 & 2
\end{array}\right], \quad B=\left[\begin{array}{rr}
4 & 8 \\
-2 & -4 \\
1 & 10
\end{array}\right]$$ (a)
(b)
(c)
STEP 1
1. Matrices and are both matrices.
2. Matrix addition and subtraction require matrices to have the same dimensions.
3. Scalar multiplication of a matrix involves multiplying every element of the matrix by the scalar.
STEP 2
1. Check if is possible and calculate it.
2. Check if is possible and calculate it.
3. Calculate .
4. Check if is possible and calculate it.
STEP 3
Check if is possible by verifying that both matrices have the same dimensions. Since both and are matrices, addition is possible.
Calculate by adding corresponding elements:
\[ A + B = \left[\begin{array}{rr}
6 & -2 \\
2 & 5 \\
-3 & 2
\end{array}\right] + \left[\begin{array}{rr}
4 & 8 \\
-2 & -4 \\
1 & 10
\end{array}\right] = \left[\begin{array}{rr}
6+4 & -2+8 \\
2+(-2) & 5+(-4) \\
-3+1 & 2+10
\end{array}\right] = \left[\begin{array}{rr}
10 & 6 \\
0 & 1 \\
-2 & 12
\end{array}\right] \]
STEP 4
Check if is possible by verifying that both matrices have the same dimensions. Since both and are matrices, subtraction is possible.
Calculate by subtracting corresponding elements:
\[ A - B = \left[\begin{array}{rr}
6 & -2 \\
2 & 5 \\
-3 & 2
\end{array}\right] - \left[\begin{array}{rr}
4 & 8 \\
-2 & -4 \\
1 & 10
\end{array}\right] = \left[\begin{array}{rr}
6-4 & -2-8 \\
2-(-2) & 5-(-4) \\
-3-1 & 2-10
\end{array}\right] = \left[\begin{array}{rr}
2 & -10 \\
4 & 9 \\
-4 & -8
\end{array}\right] \]
STEP 5
Calculate by multiplying each element of matrix by 3:
\[ 3A = 3 \times \left[\begin{array}{rr}
6 & -2 \\
2 & 5 \\
-3 & 2
\end{array}\right] = \left[\begin{array}{rr}
3 \times 6 & 3 \times (-2) \\
3 \times 2 & 3 \times 5 \\
3 \times (-3) & 3 \times 2
\end{array}\right] = \left[\begin{array}{rr}
18 & -6 \\
6 & 15 \\
-9 & 6
\end{array}\right] \]
SOLUTION
Check if is possible by verifying that both matrices have the same dimensions. Since both and will be matrices, subtraction is possible.
First, calculate :
\[ 4B = 4 \times \left[\begin{array}{rr}
4 & 8 \\
-2 & -4 \\
1 & 10
\end{array}\right] = \left[\begin{array}{rr}
4 \times 4 & 4 \times 8 \\
4 \times (-2) & 4 \times (-4) \\
4 \times 1 & 4 \times 10
\end{array}\right] = \left[\begin{array}{rr}
16 & 32 \\
-8 & -16 \\
4 & 40
\end{array}\right] \] Now, calculate :
\[ 3A - 4B = \left[\begin{array}{rr}
18 & -6 \\
6 & 15 \\
-9 & 6
\end{array}\right] - \left[\begin{array}{rr}
16 & 32 \\
-8 & -16 \\
4 & 40
\end{array}\right] = \left[\begin{array}{rr}
18-16 & -6-32 \\
6-(-8) & 15-(-16) \\
-9-4 & 6-40
\end{array}\right] = \left[\begin{array}{rr}
2 & -38 \\
14 & 31 \\
-13 & -34
\end{array}\right] \] The solutions are:
(a)
(b)
(c)
(d)