How to combine the similar items in the first grade of junior high school 1. When m = (), the algebraic expression 2x & sup2; - MXY + & frac34; X contains no XY term 2. The taxi charge standard of a city is: the starting price is 4 yuan, and the price per kilometer after 2 kilometers is 1.2 yuan. How much yuan should Zhang Liang pay for a kilometer? (expressed in algebraic formula) 3. Dividing by a number that is not zero is equal to multiplying by the reciprocal of the number? I'm a student of grade one in junior high school. I'm very dizzy about the merging of similar items in mathematics

How to combine the similar items in the first grade of junior high school 1. When m = (), the algebraic expression 2x & sup2; - MXY + & frac34; X contains no XY term 2. The taxi charge standard of a city is: the starting price is 4 yuan, and the price per kilometer after 2 kilometers is 1.2 yuan. How much yuan should Zhang Liang pay for a kilometer? (expressed in algebraic formula) 3. Dividing by a number that is not zero is equal to multiplying by the reciprocal of the number? I'm a student of grade one in junior high school. I'm very dizzy about the merging of similar items in mathematics

1. 0
2. (a-2)*1.2+4
3. a/b=a*1/b
It's too simple to see. Just like 1 + 1 = 2, we all know, but we can't tell why, ha ha