To solve this system of equations, we can use the method of substitution or elimination.

Let's use the substitution method.

From the first equation:
х + 5у = 27
=> х = 27 - 5у

Substitute this value of х into the second equation:
2(27 - 5у) - у = -1
54 - 10у - у = -1
54 - 11у = -1
-11у = -55
у = 5

Now substitute the value of у back into one of the original equations to solve for х:
х + 5(5) = 27
х + 25 = 27
х = 2

Therefore, the solution to the system of equations is х = 2 and у = 5.