45. a) 3 2 1 4y² 2x-y -2x+y 2x-5y) 4x²-y²

a) Упростим выражение $$\left(\frac{3}{2x-y} - \frac{2}{-2x+y} - \frac{1}{2x-5y}\right):\frac{4y^2}{4x^2-y^2}$$.

$$\left(\frac{3}{2x-y} + \frac{2}{2x-y} - \frac{1}{2x-5y}\right):\frac{4y^2}{4x^2-y^2}$$.

$$\left(\frac{5}{2x-y} - \frac{1}{2x-5y}\right):\frac{4y^2}{(2x-y)(2x+y)}$$.

$$\frac{5(2x-5y)-(2x-y)}{(2x-y)(2x-5y)}:\frac{4y^2}{(2x-y)(2x+y)}$$.

$$\frac{10x-25y-2x+y}{(2x-y)(2x-5y)}:\frac{4y^2}{(2x-y)(2x+y)} = \frac{8x-24y}{(2x-y)(2x-5y)}:\frac{4y^2}{(2x-y)(2x+y)} = \frac{8(x-3y)(2x-y)(2x+y)}{4y^2(2x-y)(2x-5y)} = \frac{2(x-3y)(2x+y)}{y^2(2x-5y)}$$.

Ответ: $$\frac{2(x-3y)(2x+y)}{y^2(2x-5y)}$$