If the sum of two terms = 0, then the 2 terms must have the same value but different signs
That means x and y must have the same value but different signs
Look at the given answers
The 1st, 2nd, and 4th answers are wrong because the solution of this equation must have a value of x and a value of y together
In the 3rd answer
x = 1 and y = -1
Both have the same value and different signs
Then 3rd answer is a solution
In the 5th answer
x = -2 and y = -2
They have the same value with the same signs
The 5th answer is not a solution
In the last answer
x = 0 and y = 0
They have the same value but the zero has no sign
Then substitute them in the equation to check if it is solution or not
2(0)+2(0) = 0
0 + 0 = 0
The 2 sides of the equation are equal, then
The last answer is a solution
The answer is the 3rd and last answers