B2=IF(A2>90,0.1*A2-8,IF(A2>=75,1,0.1*A2-6.5))
供参考，祝顺利。
=if(A1>90,1+0.1*(A1-90),if(A1>=75,1,if(A1>=65,1-0.1*(75-A1),"")))
