Выполните действия (номера 59-66)

59. $\frac{3+x}{4} + \frac{3x-7}{4} = \frac{3+x+3x-7}{4} = \frac{4x-4}{4} = \frac{4(x-1)}{4} = x-1$ 60. $\frac{a+4}{b} + \frac{2a}{b} = \frac{a+4+2a}{b} = \frac{3a+4}{b}$ 61. $\frac{2a+b}{a-2b} + \frac{a+3b}{2b-a} = \frac{2a+b}{a-2b} - \frac{a+3b}{a-2b} = \frac{2a+b-a-3b}{a-2b} = \frac{a-2b}{a-2b} = 1$ (при $a \neq 2b$) 62. $\frac{8+z}{1-t} - \frac{t-3z}{t-1} = \frac{8+z}{1-t} + \frac{t-3z}{1-t} = \frac{8+z+t-3z}{1-t} = \frac{8-2z+t}{1-t}$ 63. $\frac{2x-1}{y-x} + \frac{x-4}{x-y} = \frac{2x-1}{y-x} - \frac{x-4}{y-x} = \frac{2x-1-x+4}{y-x} = \frac{x+3}{y-x}$ 64. $\frac{a+5}{4x} \cdot \frac{2x}{a+5} = \frac{(a+5) \cdot 2x}{4x \cdot (a+5)} = \frac{2x}{4x} = \frac{1}{2} = 0,5$ (при $a \neq -5, x \neq 0$) 65. $\frac{a^2-b^2}{2a^2b} \cdot \frac{4ab}{a+b} = \frac{(a-b)(a+b)}{2a^2b} \cdot \frac{4ab}{a+b} = \frac{(a-b) \cdot 4ab}{2a^2b} = \frac{2(a-b)}{a} = 2 - \frac{2b}{a}$ (при $a \neq 0, b \neq 0, a \neq -b$) 66. $\frac{2t}{t-2} : \frac{3t}{t-2} = \frac{2t}{t-2} \cdot \frac{t-2}{3t} = \frac{2t}{3t} = \frac{2}{3}$ (при $t \neq 2, t \neq 0$)