A、F=AB
B、<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/1522310887457f6dbb07e2b314f1b95451ec893f0a3bfimage2.jpeg">
C、<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/1522310887550e6f9e89817144b8ea2428d439b1e8a22image3.jpeg">
D、F=A+B