Question

急急急 6道题，悬赏10分

速度回答啊

Answer 1

(23)原式=(x^2-xy-6y^2)-(x^2-y^2)+5y^2
=x^2-xy-6y^2-x^2+y^2+5y^2
= -xy

(24)原式=x^2-4y^2-4xy+4y^2
=x^2-4xy

(25)原式=8a^3+12a^2b+18ab^2-12a^2b-18ab^2-27b^3
=8a^3-27b^3

(26)原式=(3x^2+5xy-2y^2)-(2x^2+11xy-6y^2)
=3x^2+5xy-2y^2-2x^2-11xy+6y^2
=x^2-6xy+4y^2

(27)原式= -(3a-2b)(3a-b)-(6a^2-ab-b^2)
= -9a^2+9ab-2b^2-6a^2+ab+b^2
= -15a^2+10ab-b^2

(28)原式=9x^2-2(x^2-7x+10)
=9x^2-2x^2+14x-20
=7x^2+14x-20

Answer 2

您好，这里是@念西零 为您解答，希望得到您的满意评价!
(23)原式=(x^2-xy-6y^2)-(x^2-y^2)+5y^2
=x^2-xy-6y^2-x^2+y^2+5y^2
= -xy

(24)原式=x^2-4y^2-4xy+4y^2
=x^2-4xy

(25)原式=8a^3+12a^2b+18ab^2-12a^2b-18ab^2-27b^3
=8a^3-27b^3

(26)原式=(3x^2+5xy-2y^2)-(2x^2+11xy-6y^2)
=3x^2+5xy-2y^2-2x^2-11xy+6y^2
=x^2-6xy+4y^2

(27)原式= -(3a-2b)(3a-b)-(6a^2-ab-b^2)
= -9a^2+9ab-2b^2-6a^2+ab+b^2
= -15a^2+10ab-b^2

(28)原式=9x^2-2(x^2-7x+10)
=9x^2-2x^2+14x-20
=7x^2+14x-20 有不解的地方欢迎追问!

【^2为某数的平方】

Answer 3

(23)原式=(x^2-xy-6y^2)-(x^2-y^2) 5y^2
=x^2-xy-6y^2-x^2 y^2 5y^2
= -xy
(24)原式=x^2-4y^2-4xy 4y^2
=x^2-4xy
(25)原式=8a^3 12a^2b 18ab^2-12a^2b-18ab^2-27b^3
=8a^3-27b^3
(26)原式=(3x^2 5xy-2y^2)-(2x^2 11xy-6y^2)
=3x^2 5xy-2y^2-2x^2-11xy 6y^2
=x^2-6xy 4y^2
(27)原式= -(3a-2b)(3a-b)-(6a^2-ab-b^2)
= -9a^2 9ab-2b^2-6a^2 ab b^2
= -15a^2 10ab-b^2
(28)原式=9x^2-2(x^2-7x 10)
=9x^2-2x^2 14x-20
=7x^2 14x-20

Answer 4

太简单了，初中同学，教你一招，找相同字母，去括号，由小到中括号，合并同类项，解出答案。交卷