Решите пожалуйста!!!

$a)$

$\frac{1}{7} *x^2 \sqrt{49x^6},$ $x \geq 0$

$\frac{1}{7} *x^2* \sqrt{49x^6} = \frac{1}{7} *x^2* \sqrt{(7x^3)^2} =\frac{1}{7} *x^2* |7x^3| =\frac{1}{7} *x^2* 7x^3 =x^5$

$b)$

$-5*y^6* \sqrt{ \frac{1}{81y^{10}} },$ $y\ \textless \ 0$

$-5*y^6* \sqrt{ \frac{1}{81y^{10}} }=-5*y^6* \sqrt{ (\frac{1}{9y^{5}}) }=-5*y^6*| \frac{1}{9y^{5}}|=$ $=-5*y^6*(- \frac{1}{9y^{5}})= \frac{5}{9} y$