Question

виконай дії 7/(2b+3)+3/(3-2b)+(2b+15)/(4b^2-9)

Answer 1

Объяснение:

$\displaystyle\\\frac{7}{2b+3} +\frac{3}{3-2b} +\frac{2b+15}{4b^2-9} =\frac{7}{2b+3} -\frac{3}{2b-3} +\frac{2b+15}{(2b+3)*(2b-3)} =\\\\\\\frac{7*(2b-3)-3*(2b+3)+2b+15}{(2b+3)*(2b-3)} =\frac{14b-21-6b-9+2b+15}{(2b+3)*(2b-3)} =\\\\\\=\frac{10b-15}{(2b+3)*(2b-3)}=\frac{5*(2b-3)}{(2b+3)*(2b-3)}=\frac{5}{2b+3}.$