Find a few math problems that are simplified first and then evaluated, and don t be too complicated

4, (the first math problem) first simplify the Dan brigade, and then evaluate the value [urgent].

1 2x-2 (x-1 3y) + 3 2x + 1 3y ), where x = -2 and y = 2 3

Note the imitation blindness: first find the previous formula to prepare the space, and then write when x=-2, y=2 3, the original formula =.】

3ab-4ab+8ab-7ab+ab=___5a＋3b-2a＋（2b＋3b）=___2a-b2+c-d3=2a+( d3=2a-d3-( =c-(

2x-(x+3y)-(x-y)-(x-y)=（ ）=2x-x+3y+x+y-x+y

x+5y is known as x 0, y 0, simplification|x+y|-|5-x-y|=___7x2+6x+13x2-4x-5x2=___3b＋5a-5b＋10b=___

The simplified algebraic formula x-[y-2x-(x+y)] is equal to

1．(3a2-4ab-5b2)-(2b2-5a2+2ab)-(6ab)．

2．xy-(2xy-3z)+(3xy-4z)．

3．(-3x3+2x2-5x+1)-(5-6x-x2+x3)．

4．3x-(2x-4y-6x)+3(-2z+2y)．

5．(-x2+4+3x4-x3)-(x2+2x-x4-5)．

6 If a=5a2-2ab+3b2, b=-2b2+3ab-a2, calculate a+b

7．5m2n+(-2m2n)+2mn2-(+m2n)．

8．2(x2-2xy+y2-3)+(x2+y2)-(x2+2xy+y2)．

9．2(a2-ab-b2)-3(4a-2b)+2(7a2-4ab+b2)．

10 Find (3x2y-2xy2)-(xy2-2x2y), where x=-1 and y=2

11 Known|x+1|+(y-2)2=0, find the value of algebraic equation 5(2x-y)-3(x-4y).

12 When p=a2+2ab+b2, q=a2-2ab-b2, find p-[q-2p-(p-q)].

13 Find the value of 2x2-{-3x+5+[4x2-(3x2-x-1)]}, where x=-3

14 When x=-2, y=-1, z=3, find the value of 5xyz-{2x2y-[3xyz-(4xy2-x2y)]}

15 Knowing a=x3-5x2, b=x2-6x+3, find a-3(-2b).

16 Remove parentheses: {-a+b)] ｝a-b)]｝

17 Remove parentheses: -[x)-y]-[y)-(x)].

18 Consolidated homogeneous items: 5m2n+5mn2-mn+3m2n-6mn2-8mn

19 Calculate the value of 4x2-3[x+4(1-x)-x2]-2(4x2-1).

20. Knowing a=11x3+8x2-6x+2, b=7x3-x2+x+3, find 2(3a-2b).

When x=-2, y=2 3.

Original = -3 * (-2) + 4 9

6 and 4/9

**Format.

I don't know, ah

Quarter Pin (-4x Sling+2x-8) -(Half x-1) -x 2+1 2x-8-1 2x+1

x 2-77 and 1 4

5a -3b )+a +b )-5a +3b )5a -3b +a +b -5a -3b a Kaidou regret-5b

Original = (x-3)(x+3) -x+3)(x+5)(x-3) = (x-3) (x+3) (x+3) (x+5) (x-3) = (x-3) (x+3) (x+3-x-5).

2(x-3)(x+3)

Because x=-3

So the formula = 0

In other words, the inner one (x 2+2x-15) uses the multiplication of crosses, and now I learned it in the first year of junior high school