\(\left(1+\frac{b^2+c^2-a^2}{2bc}\right).\frac{1+\frac{a}{b+c}}{1-\frac{a}{b+c}}.\frac{b^2+c^2-\left(b-c\right)^2}{a+b+c}\)
= \(\left(1+\frac{\left(b+c\right)^2-2bc-a^2}{2bc}\right).\frac{\frac{a+b+c}{b+c}}{\frac{b+c-a}{b+c}}.\frac{\left(b+c\right)^2-2bc-\left(b-c\right)^2}{a+b+c}\)
= \(\left(1+\frac{\left(b+c-a\right)\left(b+c+a\right)-2bc}{2bc}\right).\frac{a+b+c}{b+c-a}.\frac{\left(b+c-b+c\right)\left(b+c+b-c\right)-2bc}{a+b+c}\)
= \(\left(1+\frac{\left(b+c-a\right)\left(b+c+a\right)}{2bc}-1\right).\frac{a+b+c}{b+c-a}.\frac{4bc-2bc}{a+b+c}\)
= \(\frac{\left(b+c-a\right)\left(b+c+a\right)}{2bc}.\frac{2bc}{b+c-a}\)
= \(\frac{\left(b+c-a\right)\left(b+c+a\right)}{b+c-a}\)
= \(b+c+a\)