augmented matrix
+8 +2 -68
-7 -1 +55
you have two rows, three columns
now go to
http://www.gregthatcher.com/Mathematics/GaussJordan.aspx
How do I use gauss-jordan to solve this? Can you explain the steps and show what you multiplied, added, subtracted, etc to each row?
8x + 2y = -68
-7x - y = 55
3 answers
-7
-6
-6
divide first row by 8 to get 1 in upper left
1 1/4 -17/2
add 7 times new first row to second to get 0 below the one
1 +1/4 -17/2
0 +3/4 -9/2
subtract 1/3 times row 2 from row 1 to get rid of that 1/4 in row 1
1 0 -7
0 3/4 -9/2
multiply second row by 4/3 to get 1 in 2,2 spot
1 0 -7
0 1 -6
done
1 x + 0 y = -7
0 x + 1 y = -6
1 1/4 -17/2
add 7 times new first row to second to get 0 below the one
1 +1/4 -17/2
0 +3/4 -9/2
subtract 1/3 times row 2 from row 1 to get rid of that 1/4 in row 1
1 0 -7
0 3/4 -9/2
multiply second row by 4/3 to get 1 in 2,2 spot
1 0 -7
0 1 -6
done
1 x + 0 y = -7
0 x + 1 y = -6
5 answers