Помогите 1 вариант!!!!!!!!!!!!!!!

a) $\frac{ab^2}{5c}* \frac{2c^3}{a^2b} = \frac{2ab^2c^3}{5ca^2b}= \frac{2c^2b}{5a}$

б) $\frac{a+b}{2ab} : \frac{a+b}{8a^2b^2} = \frac{a+b}{2ab \frac{a+b}{8a^2b^2} } =$

$= \frac{8a^2b^2(a+b)}{2ab(a+b)}= \frac{8a^2b^2}{2ab}= \frac{4a^2b^2}{ab}=$

$=4ab$

в) $(4a^4b^3):( \frac{2a^3b}{a+b} )^3=(4a^4b^3):( \frac{2^3a^9b^3}{(a+b)^3} )=$

$= \frac{4a^4b^3(a+b)^3}{2^3a^{3*3}b^3}= \frac{4a^4(a+b)^3}{2^3a^{3*3}}=$

$= \frac{4(a+b)^3}{8a^5}= \frac{(a+b)^3}{2a^5}$

г) $\frac{5a-x}{5a+x} *(5a+x)^2= \frac{(5a-x)(5a+x)^2}{5a+x}= (5a-x)(5a+x)$