(2) 10 km/h in x-0.2.

(3)t- 1+0。

2. Algebraic expressions are: second, fourth, seventh and eighth; The scores are: first, third, fifth, sixth and last;

3.( 1)X is not equal to 0; (2)3-X is not equal to 0; (3)X is not equal to minus three fifths; (4)X is not equal to 4.

4.( 1) and (2) are equal, which can be obtained by using the basic properties of fractions.

5.( 1)X？ 5y； (2)-2b a； ③ 3)-4m of-3N; (4)2y x

6.1in (1) 5x;

(2) 3b+2c of a;

(3)3a+b；

(4) 2 x-6 models

7.( 1)6y？ 2 xy

(2)3a？ b？ BC18; ;

(3)2(x+y？ )2 xy

(4) 4m in (2m+3) (2m-3)？ - 12m+9

8.( 1)x is neither equal to 0 nor equal to1;

(2)x is an arbitrary real number.

W+65438+12000-120w in 9.0.

Every p10.m+2n+q;

1 1.2(a+b) (a+b)？ = half a+b (m);

12.( 1) is correct; (2) incorrect. The correct answer is: (x-y)? Xy-x？ =(y-x)？ X (y-x) = x of y-x;

13( 1)x is not equal to1;

(2)5a-b=0 and a+b is not equal to 0;

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(1) 4a of 1.c;

(2)yz is 21y; ;

(3) n in m? ;

(4)-4x y

2.( 1)a-b 12a； ;

(2)3x(x+2)x-2y；

(3)x+6 in x;

(4) x-y； of-x;

3.( 1)2b？ 5 points;

(2)﹣2;

(3) the fourth power of z and the sixth power of x y? ;

5 out of 4 4ab

Hope to adopt