Задание 508

Решение:

• \({\largeа)}\ \frac{3}{a+b}+\frac{5}{a+b}=\frac{3+5}{a+b}=\frac{8}{a+b}\)

• \({\largeб)}\ \frac{2}{x-1}-\frac{1}{x-1}=\frac{2-1}{x-1}=\frac{1}{x-1}\)

• \({\largeв)}\ \frac{a+3}{a+b}+\frac{a-3}{a+b}=\frac{a+3+a-3}{a+b}=\frac{2a}{a+b}\)

• \({\largeг)}\ \frac{m+1}{m+n}-\frac{3-m}{m+n}=\frac{ m+1-(3-m)}{m+n}=\frac{m+1-3+m}{m+n}=\frac{2m-2}{m+n}=\frac{ 2(m-1)}{m+n}\)

• \({\largeд)}\ \frac{2x-4}{x-3}-\frac{3x+5}{x-3}=\frac{ 2x-4-(3x+5)}{x-3}=\frac{2x-4-3x-5}{x-3}=\frac{{-}x-9}{x-3}={-}\frac{x+9}{x-3}\)

• \({\largeе)}\ \frac{7p-1}{p+1}-\frac{7-p}{p+1}=\frac{ 7p-1-(7-p)}{p+1}=\frac{7p-1-7+p}{p+1}=\frac{8p-8}{p+1}=\frac{ 8(p-1)}{p+1}\)