Помогите пожалуйста 27 28 29 б г е

27 а) $\frac{y^{3}}{y^{3}+y^{2}} = \frac{y}{y+1}$
27 б) $\frac{5a^{2}}{a^{4}+a^{2}} = \frac{5}{a^{2}+1}$
27 в) $\frac{x^{5}+x^{3}}{x^{2}+1} = x^{3}$
27 г) $\frac{b^{5}-b^{4}}{b^{5}} =\frac{b-1}{b}$
27 д) $\frac{m^{4}-m^{3}}{m^{2}+m^{3}} =\frac{m^{2}-m}{1+m}$
27 е) $\frac{n^{2}-n-1}{n^{4}-n^{3}-n^{2}} =\frac{1}{n^{2}}$

28 а) $\frac{x^{2}-9y^{2}}{x+3y} = x-3y$
28 б) $\frac{a+2b}{a^{2}+4ab+4b^{2}} = \frac{1}{a+2b}$
28 в) $\frac{m^{2}-n^{2}}{mn-n^{2}} =\frac{m+n}{n}$
28 г) $\frac{ax-ay}{x^{2}-2xy+y^{2}} =\frac{a}{x-y}$
28 д) $\frac{2ab-6a}{b^{2}-6b+9} =\frac{2a}{b-3}$
28 е) $\frac{5n^{2}+10n}{n^{2}-4} =\frac{5n}{n-2}$

29 б) $\frac{3ac+6a}{ac^{2}+2ac} = \frac{3a}{ac} =\frac{3}{c}$
29 г) $\frac{4a-2a^{2}}{4b-2ab} =\frac{2a*(2-a)}{2b*(2-a)}=\frac{a}{b}$
29 е) $\frac{ac^{2}-bc^{2}}{c*(a^{2}-b^{2})} =\frac{c}{a+b}$