2. Senior one mathematics: use letters to represent numbers.
Let n be an integer and use algebraic expressions to represent the following numbers.
1)3 consecutive integers ().
2)3 consecutive odd numbers ().
3) Numbers divisible by 3 ().
Answer:
1.N，N+ 1，N+2 ^ 2。 2N+ 1，2N+3，2N+5 3。 3N
Calculate.
3ab-4ab+8ab-7ab+ab=______。
7x-(5x-5y)-y=______。
23 a3 BC 2- 15 ab2c+8 ABC-24 a3 BC 2-8 ABC = _ _ _ _ _ _。
-7x 2+6x+ 13 x2-4x-5x 2 = _ _ _ _ _ _。
2y+(-2y+5)-(3y+2)=______。
2.2N+ 1，2N+3，2N+5
3.3N