Answer: (B) –1
Step-by-step explanation
We are given functions f(x) and g(x), and we are aked to fins a when f(a) = g(a). Therefore, we have to set the equations equal to each other. Additionally, we have to replace x with a:
![f(a)=g(a)](https://img.qammunity.org/2023/formulas/mathematics/college/kn3pe5o9hnivbkrjc9zths8u40gocj6gt4.png)
![a(a+1)=(a^2-1)](https://img.qammunity.org/2023/formulas/mathematics/college/kjeefctfawfoz41o5e8ngd2dyvxuflr98s.png)
First, we have to multiply the a outside the parenthesis times the terms inside the parenthesis:
![a^2+a=a^2-1](https://img.qammunity.org/2023/formulas/mathematics/college/3yh6q4ututegkku39ycxmu63m49plo0tyc.png)
Then, we have to get all the similar terms to each side of the equation and simplify:
![a^2-a^2+a=-1](https://img.qammunity.org/2023/formulas/mathematics/college/w43zcaagw3jf12diiaxmkk7sn7ocpak8bo.png)
![a=-1](https://img.qammunity.org/2023/formulas/mathematics/high-school/ibedswn114hbuv3jrrbj1n4n0sejyq9m45.png)