Sagot :
The first one has a negative. You shouldn't have a negative isolated variable,
-x = 5y -1, Multiply everything by -1,
x = -5y + 1,
For the second one, you isolate the x,
x + 2y = 13, subtract 2y from both sides,
x = 13 - 2y.
-x = 5y -1, Multiply everything by -1,
x = -5y + 1,
For the second one, you isolate the x,
x + 2y = 13, subtract 2y from both sides,
x = 13 - 2y.
[tex]x=5y-1\\
x+2y=13\\\\
5y-1+2y=13\\
7y=14\\
y=2\\\\
x=5\cdot2-1\\
x=9\\\\
\boxed{(x,y)=(9,2)}[/tex]