Question

упростите выражение

Answer 1

$(3+ \frac{ a^{2}+9b^{2}- c^{2}}{2ab}) : (a+3b+c)*2ab = ( \frac{6ab+a^{2}+9b^{2}- c^{2}}{2ab})* \frac{1}{a+3b+c}*2ab= \\ = \frac{(a^{2}+6ab+9b^{2}- c^{2})*2ab}{2ab*(a+3b+c)}= \frac{ (a+3b)^{2}- c^{2} }{a+3b+c}= \frac{(a+3b+c)*(a+3b-c)}{a+3b+c}=a+3b-c$