15.37 * 7.89-9.37 * 7.89 + 2.11-9.37 * 2.11

15.37 * 7.89-9.37 * 7.89 + 2.11-9.37 * 2.11

Wrong title:
15.37×7.89-9.37×7.89+15.37×2.11-9.37×2.11
=(15.37-9.37)*7.89+(15.37-9.37)*2.11=6*(7.89+2.11)
=60

Calculation: 0.1 + 0.3 + 0.5 + 0.7 + 0.9 + 0.11 + 0.13 + 0.15 + +0.97+0.99．

（0.1+0.99）×[（0.99-0.1）÷0.2+1]÷2，=1.09×50÷2，=27.25．

Add ＞, ＜, or "=" to the fourth grade math problem, and explain the reason 89 × 97 × 97 × 89 (37 + 22) × 15 × 37 × (22 × 15) 6 × 9
Add ">, <, or" = "in the 0 and explain the reasons
1、89×97○97×89
2、（37＋22）×15○37×(22×15)
3、 6×99＋6○6×100
4、 （5＋13）×20○5×20×13

Question 1: = we know 89 * 97 = 97 × 89 by the law of exchange question 2: < 37 + 22 = 59 formula is equal to 59 × 15, the following formula is equal to (37 × 22) × 15 obviously 59 < 37 × 22 question 3: = 6 × 99 + 6 = 6 × 99 + 6 × 1 distribution law is known 6 × (99 + 1) = 6 × 100 question 4: < 5 + 13

Calculation: - (1 2 / 3-4 11 / 12) - (13 11 / 18 + 3 1 / 4)

-(1 and 2 / 3-4 and 11 / 12) - (13 and 11 / 18 + 3 and 1 / 4)
=-1 and 2 / 3 + 4 and 11 / 12-13 and 11 / 18-3 and 1 / 4
=-1 8 / 12 + 4 11 / 12-3 3 / 12-13 11 / 18
=-1,8 / 12-3,3 / 12 + 4,11 / 12-13,11 / 18
=-4 11 / 12 + 4 11 / 12-13 11 / 18
=-13 and 11 / 18