Ответ:
- \[\frac{4y-1}{5y}-\frac{2y-7}{5y}+\frac{3y-1}{5y}=\frac{4y-1-2y+7+3y-1}{5y}=\frac{5y+5}{5y}=\frac{y+1}{y}.\]
- \[\frac{7x-3}{4x}-\frac{x-4}{4x}-\frac{5-2x}{4x}=\frac{7x-3-x+4-5+2x}{4x}=\frac{8x-4}{4x}=\frac{2x-1}{x}.\]
- \[\frac{a-8}{a^2-25}+\frac{13}{a^2-25}=\frac{a-8+13}{a^2-25}=\frac{a+5}{(a-5)(a+5)}=\frac{1}{a-5}.\]
- \[\frac{a^2-b}{b^2+6b+9}-\frac{a-b}{b^2+6b+9}=\frac{a^2-b-a+b}{b^2+6b+9}=\frac{a^2-a}{(b+3)^2}=\frac{a(a-1)}{(b+3)^2}.\]
Ответ: а) \(\frac{y+1}{y}\); б) \(\frac{2x-1}{x}\); в) \(\frac{1}{a-5}\); г) \(\frac{a(a-1)}{(b+3)^2}\).
