The real numbers aaa and bbb satisfy 3a+2b=7,2a+3b=8.3a+2b=7,\qquad 2a+3b=8.3a+2b=7,2a+3b=8. What is the value of a2−b2a^2-b^2a2−b2? A−3-3−3B−1-1−1C111D333E999