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