check it yourself like this:
11 + (-.7) = -15(y) ?????
I think x = 19 and y = -2
http://www.idomaths.com/gauss_jordan.php
with
+1 15 -11
+2 -5 +48
Can you please advise if I worked this problem correctly:
11 + x = -15y
2x - 5y = 48
15y = 11+x
y = .73 + 15x
2x (.73 + 15X) - 48
2x -3.65 -75x = 48
-73x - 3.65 = 48
x = 51.65
x = -.70
2 answers
Rewrite your equations:
11 + x = - 15 y Subtract 11 to both sides
11 + x - 11 = - 15 y - 11
x = - 15 y - 11 Add 15 y to both sides
x + 15 y = - 15y - 11 + 15 y
x + 15 y = - 11
2 x - 5 y = 48 Multiply both sides by 3
2 x * 3 - 5 y * 3 = 48 * 3
6 x - 15 y = 144
Now your system become:
x + 15 y = - 11
6 x - 15 y = 144
________________
x + 15 y = - 11
+
6 x - 15 y = 144
________________
x + 6x + 15 y - 15 y = - 11 + 144
7 x = 133 Divide both sides by 7
x = 133 / 7
x = 19
Replace this value in equation:
11 + x = - 15y
11 + 19 = - 15 y
30 = - 15 y Divide both sides by - 15
30 / - 15 = y
- 2 = y
y = - 2
Solution:
x = 19 and y = - 2
Proof:
11 + x = -15 y
11 + 19 = - 15 * ( - 2 )
30 = 30
2 x - 5 y = 48
2 * 19 - 5 * ( - 2 ) = 48
38 + 10 = 48
48 = 48
11 + x = - 15 y Subtract 11 to both sides
11 + x - 11 = - 15 y - 11
x = - 15 y - 11 Add 15 y to both sides
x + 15 y = - 15y - 11 + 15 y
x + 15 y = - 11
2 x - 5 y = 48 Multiply both sides by 3
2 x * 3 - 5 y * 3 = 48 * 3
6 x - 15 y = 144
Now your system become:
x + 15 y = - 11
6 x - 15 y = 144
________________
x + 15 y = - 11
+
6 x - 15 y = 144
________________
x + 6x + 15 y - 15 y = - 11 + 144
7 x = 133 Divide both sides by 7
x = 133 / 7
x = 19
Replace this value in equation:
11 + x = - 15y
11 + 19 = - 15 y
30 = - 15 y Divide both sides by - 15
30 / - 15 = y
- 2 = y
y = - 2
Solution:
x = 19 and y = - 2
Proof:
11 + x = -15 y
11 + 19 = - 15 * ( - 2 )
30 = 30
2 x - 5 y = 48
2 * 19 - 5 * ( - 2 ) = 48
38 + 10 = 48
48 = 48