Refer to the image below. The unit load is $200l\frac{b}{f}t$ and the concentrated load $P$ is $2,400lbs.$ Use ASD Method $($no factoring needed$).$ R$1$ is the roller support and R$2$ is the pin support.

Determine R$1.$

$4,320lbs$

$2,880lbs$

$1,920lbs$

$1,440lbs$