SOLUTION: Which matrix equation has the solution X = [[3][-5]] A) [[9 5][7 -4]]X=[[2][1]] B) [[9 5][7 4]]X=[[2][1]] C) [[9 5][-7 4]]X=[[2][1]] D) [[-9 5][7 4]]X=[[2][1]] In ca

Algebra ->  Matrices-and-determiminant -> SOLUTION: Which matrix equation has the solution X = [[3][-5]] A) [[9 5][7 -4]]X=[[2][1]] B) [[9 5][7 4]]X=[[2][1]] C) [[9 5][-7 4]]X=[[2][1]] D) [[-9 5][7 4]]X=[[2][1]] In ca      Log On


   

Question 1118973: Which matrix equation has the solution X = [[3][-5]]
A) [[9 5][7 -4]]X=[[2][1]]
B) [[9 5][7 4]]X=[[2][1]]
C) [[9 5][-7 4]]X=[[2][1]]
D) [[-9 5][7 4]]X=[[2][1]]
In case of any confusion or mistakes, I have included a screenshot. Especially as I understand this is a slightly unorthodox way of writing matrices.
https://postimg.cc/image/7uo41eglj/
Answer by greenestamps(13203) About Me  (Show Source):
You can put this solution on YOUR website!


Option A, translated into algebra, says
9%283%29%2B5%28-5%29+=+2 and 7%283%29-4%28-5%29+=+1

Since the first equation is true but the second is not, option A is not the right matrix equation.

Check each of the other options to find the right one.

Note that all the options have the same second matrix except for the signs, so it should be easy to find the correct one.