A <img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251103/24021581_0_1.png"> B
Y=AB C
<img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251103/24021581_0_2.png"> D
<img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251103/24021581_0_3.png">