Сократите дробь. Буду благодарна.

a) [latex] \frac{(y)^2-(x)^2}{(x)^2-2*(x)*(y)+(y)^2} = \frac{(y-x)(y+x)}{(x-y)^2} =\frac{(-1)*(x-y)(x+y)}{(x-y)(x-y)}= -\frac{x+y}{x-y}. [/latex] b) [latex] \frac{4t^2-2t+1}{(2t)^3+(1)^3} = \frac{4t^2-2t+1}{(2t+1)((2t)^2-2t*1+1^2)} = \frac{(4t^2-2t+1)*1}{(2t+1)(4t^2-2t+1)} = \frac{1}{2t+1}. [/latex]