Answer? + 10a+25=(a+5)？ =-|b-3|, that is to say, the formulas before and after are all 0, so we can know that a=-5 and b=3.

(a-b)? =(-5-3)? =64，b？ =9，b？ =27，a？ +ab？ -2a？ b=- 125-45- 150=-320，ab+b？ =- 15+9=-6，b？ -a？ =9-25=- 16, then the whole formula is equal to -5/8.