1. 解方程：$\frac{x+2}{4} - \frac{4x-5}{20} = \frac{3-x}{5}.$

1. 拆项,得$\frac{x}{4}+\frac{1}{2}-(\frac{x}{5}-\frac{1}{4})=\frac{3}{5}-\frac{x}{5}.$ 去括号,得$\frac{x}{4}+\frac{1}{2}-\frac{x}{5}+\frac{1}{4}=\frac{3}{5}-\frac{x}{5}.$ 移项、合并同类项,得$\frac{x}{4}=-\frac{3}{20},$解得$x=-\frac{3}{5}.$

2. 解方程：$\frac{4-6x}{0.03} -6.5 = \frac{0.02-2x}{0.02} -7.5$

2. 原方程可化为$\frac{400-600x}{3}=\frac{2-200x}{2}-1.$ 去分母,得$400-600x=3-300x-3.$ 移项、合并同类项,得$-300x=-400,$解得$x=\frac{4}{3}.$

3. 解方程：$\frac{1}{2}\{ \frac{1}{3}[ \frac{1}{4}( \frac{1}{5}x -1 )+2 ]+1 \}=1$

3. 去大括号,得$\frac{1}{3}[\frac{1}{4}(\frac{1}{5}x-1)+2]+1=2.$ 移项、合并同类项,得$\frac{1}{3}[\frac{1}{4}(\frac{1}{5}x-1)+2]=1.$ 去中括号,得$\frac{1}{4}(\frac{1}{5}x-1)+2=3.$ 移项、合并同类项,得$\frac{1}{4}(\frac{1}{5}x-1)=1.$ 去小括号,得$\frac{1}{5}x-1=4.$ 移项、合并同类项,得$\frac{1}{5}x=5.$ 两边同除以$\frac{1}{5},$得$x=25.$

4. 解方程：$5(2x+3)-\frac{3}{4}(x-2)=2(x-2)-\frac{1}{2}(2x+3).$

4. 把$2x+3,x-2$看作一个整体,移项、合并同类项,得$\frac{11}{2}(2x+3)=\frac{11}{4}(x-2).$ 去分母,得$22(2x+3)=11(x-2).$ 去括号,得$44x+66=11x-22.$ 移项、合并同类项,得$33x=-88,$解得$x=-\frac{8}{3}.$