Question

подайте у вигляді дробу ​

Answer 1

Ответ:

$\displaystyle \frac{15b-2}{10b^2}+\frac{5+b}{5b^3}=\frac{15b^2-2b+10+2b}{10b^3}=\frac{15b^2+10}{10b^3}=\frac{3b^2+2}{2b^3}\\\\\\x-3-\frac{x^2-x}{x+2}=\frac{(x-3)(x+2)-x^2+x}{x+2}=\frac{x^2-x-6-x^2+x}{x+2}=-\frac{6}{x+2}$

Answer 2

$1) \ \dfrac{15b-2}{10b^{2} } +\dfrac{5+b}{5b^{3} } =\dfrac{(15b-2)\cdot b+(5+b)\cdot 2}{10b^{3} } =\dfrac{15b^{2} -2b+10+2b}{10b^{3} }=\\\\\\=\dfrac{15b^{2} +10}{10b^{3} } =\dfrac{5\cdot(3b^{2}+2) }{10b^{3} } =\boxed{\dfrac{3b^{2}+2 }{2b^{3} } }$

$2) \ x-3-\dfrac{x^{2} -x}{x+2} =\dfrac{(x-3)\cdot(x+2)-x^{2} +x}{x+2} =\\\\\\=\dfrac{x^{2}+2x-3x-6-x^{2} +x}{x+2} =\boxed{-\dfrac{6}{x+2} }$