Question

请教初中数学问题，求高手解答，要有详细步骤哦~

Answer 1

(2) = (-2/4)(x^4)(y^4) + (6/2)(x^5)(y^4)z
= (1/2)(x^4)(y^4)(6xz-1)
= -1/2x^4y^4+3x^5y^4z
(3) = (3x^2+(1/2)y - (2/3)y^2)((-1/8)(x^3)(y^3))
= ((-1/8)(x^3)(y^3))(3x^2) + ((-1/8)(x^3)(y^3))(1/2y) - ((-1/8)(x^3)(y^3))(2/3y^2)
= (-3/8)x^5y^3 - (1/16)x^3y^4 +(1/8)x^3y^5
(4) = 12ab [ 2a- 3/4a + 3/4b +2/3b]
= 24a^2b - 9a^2b + 9ab^2 + 8ab^2
= 15a^2b + 17ab^2

2. We know that ab^2 = 6
ab(a^2b^5 - ab^3 -b) = ab^2 (a^2b^2 - ab^2 - 1)
= 6 (6a- 6-1)
= 36a - 42