LINEAR ALGEBRA I am trying to review for my up coming test a
LINEAR ALGEBRA: I am trying to review for my up coming test and I am having a problem determining which of the points (1,-2,-1,3),(-1,0,2,1), and (-2,-1,4,-3) satisfy the liear system
3x1 - x2 + 2x3 =1 and 2x1+3x2-1x4=-3
is there a way i can graph this to determine the answer? how would i plug it in?
Solution
(1,-2,-1,3),(-1,0,2,1), and (-2,-1,4,-3) satisfy the liear system
3x1 - x2 + 2x3 =1 and 2x1+3x2-1x4=-3
(1 , -2 , -1 ,3) :
 Check first equation.....
 3x1 - x2 + 2x3 =1
 3(1) - (-2) + 2(-1) = 1
 3 + 2 - 2 = 1
 3 = 1
 FALSE
So, not the first point
(-1,0,2,1) :
 Check first equation.....
 3x1 - x2 + 2x3 =1
 3(-1) - 0 + 2(2) = 1
 -3 + 4 = 1
 1 = 1
 TRUE
Check second equation as well
 2x1+3x2-1x4=-3
 2(-1) + 3(0) - 1 = -3
 -2 - 1 = -3
 -3 = -3
 TRUE
So, since both equations satisfy, the point is (-1,0,2,1)

