Question

因式分解,一道,解方程一道,答对追加分,

Answer 1

4x^4-2x^3y-3xy^3-9y^4

=4x^4-9y^4-2x^3y-3xy^3

={(2x^2)^2-(3y^2)^2}-xy(2x^2-3y^2)

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

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

(2 / (3x - 2c)) + (3 / (2x - 3c)) = 7 / 2c

设a = 3x - 2c b = 2x - 3c.

2 / a + 3 / b = 7 / 2c

6ac + 4bc - 7ab = 0

6c(3x - 2c) + 4c(2x - 3c) - 7(3x - 2c)(2x - 3c) = 0

14x^2 - 39cx + 22c^2 = 0

x = 2c 或 x = 11c/14