Question 16Evaluate $\frac1{a-b}+\frac1{a+b}+\frac{2a}{a^2+b^2}+\frac{4a^3}{a^4+b^4}$.$\frac{8a^7}{a^8+b^8}$$\frac{8b^7}{a^8+b^8}$$\frac{8a^7}{a^8-b^8}$$\frac{8ab}{a^8-b^8}$None of the above