Question 177938
</pre><font size=4 color=purple><b>  
I will do a few and let you do the rest
:
1. [3 4] [3]
[-1 -1]x=[2]
:
This is done with the assumption that you know how to multiply,add,and subtract matrices.
:
in this problem we have a 2x2 multiplied by a 2x1 and we of course get a 2x1 answer.
:
lets call our unknown matrix x= {{{(matrix(2,1,a,b))}}} 
so
:
{{{(matrix(2,2,3,4,-1,-1))}}}  {{{(matrix(2,1,a,b))}}}= {{{(matrix(2,1,3,2))}}}
: 
3a-4b=3.....eq 1
-1a+b=2.....eq 2
:
so now we have a set of linear equations to solve
multiply eq 2 by 3 and add the two equations together. a terms will be eliminated because 3a-3a=0. We are left with -4b+3b=9
:
-b=9
:
b=-9
:
now plug this value into either eq
:
-1a+(-9))=2--->-a=2+9--->a=-11
:
so x={{{(matrix(2,1,-11,-9))}}}
:
 3. x+[1 3 6] [8 1 0]
[-1 2 1]= [14 3 -1] 

lets call x={{{(matrix(2,3,a,b,c,d,e,f))}}}
:
so {{{(matrix(2,3,a,b,c,d,e,f))}}}+{{{(matrix(2,3,1,3,6,-1,2,1))}}}={{{(matrix(2,3,8,1,0,14,3,-1))}}}
:
a+1=8--->a=7
b+3=1--->b=-2
c+6=0--->c=-6
d-1=14-->d=15
e+2=3--->e=1
f+1=-1-->f=-2
:
x={{{(matrix(2,3,7,-2,-6,15,1,-2))}}}
:
hope that helps you on your way