Question

Which matrix is equal to the product HJ

(Picture attached)
Answer choices:
A.) [26 over 2]
B.) [80 over -44]
C.) [83 over -29]
D.) [76 over 0]

Answer 1

Multiply the first row of H and first column of J to get
2*(-1)+5*3+10*7=83 [top value]
For the second row and first column of J
-4(-1)+3(3)-6(7)=4+9-42=-29 [bottom value]

Answer 2

Option C is correct.

Explanation:

Given are two Matrix H and J

order of matrix H is 2 × 3 and order of matrix J is 3 × 1

Since column of H matrix matches with rows of J matrix.

Product possible and exist.

H×J =
`\begin{bmatrix}2 & 5 & 10\\-4 & 3 & -6\end{bmatrix}*\begin{bmatrix}-1\\3\\7\end{bmatrix}=\begin{bmatrix}2*(-1)+5*3+10*7\\ -4*(-1)+3*3+(-6)*7\end{bmatrix}`

`=\begin{bmatrix}-2+15+70\\ 4+9-42\end{bmatrix}=\begin{bmatrix}83\\ -29\end{bmatrix}`

Therefore, Option C is correct.