Since you do not use parentheses properly, there are several ways to read your system.
Your writing is ambiguous. To avoid ambiguity, use parentheses.

Is THIS modification what you want?

 = ,     (1)
 = .     (2)


Below is the solution of this system.


Since  = ,  = ,  = ,  = , you can rewrite the system (1), (2) in the form

 +  = ,      (1')
 +  = .       (2')

This system is still non-linear.
The way to solve it is to introduce new variables u =  and v = .
Then the system (1'), (2') takes the form

4u + 27v = 275,         (3)
8u +  9v = 145.         (4)

The system (3), (4) is just a linear, and we can easily solve it.
I will use the Elimination method. Multiply equation (3) by 2 (both sides). You will get

8u + 54v = 550,         (3')
8u +  9v = 145.         (4')

Now, distract (3') from (4'). You will get

54v - 9v = 550 - 145  --->  45v = 405  --->  v =  = 9.

Now recall that v = ,  or  9 = .  Hence,  y = 2,  and one unknown is just found.

Next, from (3)  u =  =  =  = 8.

Again, recall that  u = ,  or 8 = .  Hence,  x = 3.

The problem is solved.

Answer.  x = 3,  y = 2.

You can check that the solution is correct.