25-4x=16-4x
25-4x+4x=16-4x+4x
25=16
No solution
Contradiction
Answer:
-x with an exponent of 2 + y with an exponent of 2
Step-by-step explanation:
good luck
Answer is in a photo. I couldn't attach it here, but I uploaded it to a file hosting. link below! Good Luck!

Just make that number negative to find the opposite but the opposite of the negative number is going to be the original number again.