Question 1175989: Solve for X in a 2x3 matrix.
[-4 -4 -2] [9 -3 -6]
[3 -2 -6] = -5x-2 [8 6 6]
(the layout shifts after I press the preview question, but Matrix 1 first row should be [-4 -4 -2] and second row [3 -2 -6] = -5x-2
which is multiplied by matrix 2 first row : [9 -3 -6] and second row [8 6 6].
My attempt is below.
-45x-18 15x+6 30x+12
-40x-16 -30x-12 -30x-12''.
Based on the matrix definitions I stated, we know that
So,
We see that x is a matrix. Convention usually has uppercase letters as the labels of a matrix. This means it is better to use uppercase X instead of lowercase x.
This matrix has two rows and three columns.
The first row has the numbers: -2.8, 2, 2.8
The second row has the numbers: -3.8, -2, -1.2
-----------------------------------
To check this answer, we'll do the following steps
Multiply every entry in matrix X by -5. This computes the expression -5X. Let's call this result matrix C.
Multiply every entry in the matrix B by 2. We'll call this result matrix D.
Subtract the matrices C and D. The order is C-D. You'll pair up each corresponding entry when doing the subtraction. Let's call this result matrix E.
We should have these matrices: (note how A = E)
(note how A = E)
The entire right hand side of -5X-2B becomes matrix E. Since matrix A and matrix E are the same, this shows that A = E and that leads to A = -5X-2B being true as well. This confirms the answer.