The factor tree for 1,764 is shown. A factor tree starts with 1,764 on the top. 1,764 branches down to 2 on the left and 882 on the right. 882 branches down to 2 on the left and 441 on the right. 441 branches down to 9 on the left and 49 on the right. 9 branches down to 3 on the left and 3 on the right. 49 branches down to 7 on the left and 7 on the right. What is the simplest form of StartRoot 1,764 EndRoot? 21 42 32(72) 22(32)(72)