Question

Please help me answer this

Answer 1

Answer:

C

Step-by-step explanation:

You are given two matrices A and B.

1. Find 2A by multiplying each element of A by 2:

$2A=2\cdot \left(\begin{array}{ccc}-1&9&2\\10&-10&2\\-5&6&-5\end{array}\right)=\left(\begin{array}{ccc}-2&18&4\\20&-20&4\\-10&12&-10\end{array}\right)$

2. Find 4B by multiplying each element of B by 4:

$4B=4\cdot \left(\begin{array}{ccc}7&-1&-1\\6&-4&-3\\-10&10&-7\end{array}\right)=\left(\begin{array}{ccc}28&-4&-4\\24&-16&-12\\-40&40&-28\end{array}\right)$

3. Subtract two matrices 2A and 4B (from each element of matrix 2A subtract corresponding element of matrix 4B)

$2A-4B=\left(\begin{array}{ccc}-2&18&4\\20&-20&4\\-10&12&-10\end{array}\right)-\left(\begin{array}{ccc}28&-4&-4\\24&-16&-12\\-40&40&-28\end{array}\right)=\left(\begin{array}{ccc}-30&22&8\\-4&-4&16\\30&-28&18\end{array}\right)$