Sixth grade math problem. 10 points! Urgent 1. There is a score. Add 2 to his denominator to get 7 / 9. Add 3 to his denominator to get 3 / 4? 2. Simple algorithm 13.8*6.5-4.5*6.5+9.3*3.5= 248-25 9 / 20-22.05= 3. The total weight of a and B oil is 64 kg. From a barrel to B barrel, the weight of a barrel is 1 / 7 of B barrel? In addition, it should be fast and accurate

Sixth grade math problem. 10 points! Urgent 1. There is a score. Add 2 to his denominator to get 7 / 9. Add 3 to his denominator to get 3 / 4? 2. Simple algorithm 13.8*6.5-4.5*6.5+9.3*3.5= 248-25 9 / 20-22.05= 3. The total weight of a and B oil is 64 kg. From a barrel to B barrel, the weight of a barrel is 1 / 7 of B barrel? In addition, it should be fast and accurate

The least common multiple of 1.3 and 7 is 21. Let the numerator of this fraction be 21x, then the denominator after two operations is 27x and 28x respectively, and 28x-27x = 1, so x = 1, so the original fraction is 21 / 252. 1: the original formula = (13.8-4.5) * 6.5 + 9.3 * 3.5 = 9.3 * 6.5 + 9.3 * 3.5 = 9.3 * (6.5 + 3.5) = 9.3 * 10 = 93. 2: the original formula = 248 - (25 and 9