Question 9The fraction $$ \frac{a^2+b^2-c^2+2ab}{a^2+c^2-b^2+2ac} $$ is (with suitable restrictions on the values of $a,$ $b,$ and $c$):irreduciblereducible to $-1$reducible to a polynomial of three termsreducible to $\dfrac{a-b+c}{a+b-c}$reducible to $\dfrac{a+b-c}{a-b+c}$