Answer:
x + y = 2
Step-by-step explanation:
given
2x - 8 = 2y ( subtract 2y from both sides )
2x - 2y - 8 = 0 ( add 8 to both sides )
2x - 2y = 8 ( divide through by 2 )
x - y = 4
given
x² - y² = 8 ← factor left side as a difference of squares
(x - y)(x + y) = 8 ← substitute x - y = 4
4(x + y) = 8 ( divide both sides by 4 )
x + y = 2
