Junior high school mathematics problems (integral addition and subtraction) （m+2n）-（m-2n）（2ab+5a²-2b²）-（a²+2ab-2b²） 2x-3（x-2y+3z)+2（3x-3y+2z） 8m²-[4m²-2m-（2m²-5m）]

(m+2n）-（m-2n）=m+2n-m+2n=4n(2ab+5a²-2b²）-（a²+2ab-2b²)=2ab+5a²-2b²-a²-2ab+2b²=4a²2x-3（x-2y+3z)+2（3x-3y+2z）=2x-3x+6y-9z+6x-6y+4z=5x-5z8m²-[4m&sup...

1. The cube of the square B-B of the polynomial 5a-2a + the cube B of a is arranged as {} according to the descending power of A
2. If the sum of the power y of the upper right corner M-1 of 2x is still a monomial, find the value of the power n of [- M]
3. If the congeneric terms in the square - 2x + m + [- x-mx + 1] of the polynomial 3x are combined, the polynomial obtained does not contain the linear term of X, and the value of M is obtained
4. In July, the shopping mall sold a new bag, B yuan for each bag, and C yuan for turnover. In August, the shopping mall took promotional activities to give preferential treatment to the majority of students, and sold 3A new bags, with a 20% discount for each bag. Then the turnover of the new bag in August increased {} compared with that in July
5. Merge the same type in the square Y-2 / 1 x of x-3 / 1 x of X, and the final result is {}
6. If the 1-C power of the monomial 2axy and the 6-th power of the b-th power y of - 4x are the same kind, and the combined result is the 6-th power of - 2XY, then a-b-c = {}

1. The cube of - B + the square of 5a-2a, the cube of B + the cube of a b2.2x, the power of M-1 in the upper right corner + y. because of the event once formula, M-1 = 0, M = 1 (- M) ^ n = 1. When n is even and n is odd, we get the square y6 of - 13.3x ^ 2-2x + m + (- x-mx + 1) = 3x ^ 2 - (3 + m) x + m + 13 + M = 0m = 34.3a * 0.8 * b-ab5. - 6

(1) 2 (4x-0.5) (2) - 3 (1-1 / 6 times x)
(3) Negative x + (2x-2) - (3x + 5) (4) 3A ^ 2 + A ^ 2 - (2a ^ 2-2a) + (3a-a ^ 2)

（1)2（4x－0.5）
=2*4x-2*0.5
=8x-1
(2）－3（1－1/6*x）
=-3*1+3*1/6x
=-3+x/2
（3)-x＋（2x－2）－（3x＋5）
=-x+2x-2-3x-5
=-2x-7
（4） 3a^2＋a^2－（2a^2－2a)＋（3a－a^2）
=3a^2+a^2-2a^2+2a+3a-a^2
=a^2+5a

A junior high school mathematics problem (addition and subtraction of integral)
Given a = 4ab-2b ^ 2-A ^ 2, B = 3B ^ 2-2a ^ 2 + 5ab, when a = 1.5, B = - 0.5, find the value of 3b-4a. Pay attention to the case of letters, and can not be directly brought in, to use the merger of similar items, the faster the better

3B-4A=9b^2-6a^2+15ab-16ab+8b^2+4a^2=17b^2-2a^2-ab
=17＊0.25-2＊2.25+0.75
=0.5

Junior high school mathematics problems (integral addition and subtraction) （m+2n）-（m-2n） （2ab+5a²-2b²）-（a²+2ab-2b²） 2x-3（x-2y+3z)+2（3x-3y+2z） 8m²-[4m²-2m-（2m²-5m）]